| Summary: | 1920's arsenic works, flues and chimney at Devon Great Consols. Arsenic works comprising 3 calciners, grinding mill and engine house, flues and baffle chamber, further flue leading to inspection chamber and chimney to north. Devon Great Consols opened in 1844; all existing buildings were built in 1922. Slatestone and granite rubble with brick quoins to calciners and brick dressings. Calciners, grinding mill and engine house at lower level, zig-zag flues lead up to baffle chamber, further flue to north to inspection chamber and chimney. Engine house to east has large granite block platform, probably formerly had tramway leading to it from south; adjacent grinding mill has one grindstone (base) remaining on timber platform, hole at front of grindstone for crushed ore; remains of further building to east end, possibly originally calciner. Row of 3 calciners, each with pair of stoke holes to each side with brick segmental heads, lower stoke hole larger; splayed-back brick opening to former front opening at chamber height, to rear flues branched in zig-zag patterns about 10 metres uphill to baffle chamber. Flues diverted through as many channels as possible for maximum crystallisation of arsenic fumes. Baffle chamber has 8 round-arched openings to front and rear, 3 flue entries to west, each bay divided in 2 forming 16 vaulted internal chambers served by 2 flues; flues emerge to east, carried through long narrow passage about 100 metres, and merging into one flue, leading to inspection chamber below chimney, in rubble, cylindrical and tapered. Chambers and flue connected with the calcinus conform to specification dated 24th September 1866 in the lease for arsenic working. The flue to the stack should be at least 600 feet long. "The section of the main chamber and first length of the flue being of the length of 90 feet shall be of 12 feet in height and 6 feet wide. A reduction shall be allowed after the first length of flue but no part shall be less than 4 1/2 feet by 3 feet wide. The walls of the chamber and flue shall be solidly built and the thickness of at least 2 1/2 feet of masonry where the flue is of the greatest dimension and nowhere less than 2 feet. The precipitation of the arsenic sulphur gases and volatile substances which pass beyond the main flues and chambers shall be effected by means of water falls and showers". By 1870, half the world's supply of arsenic was produced here. Then the early 1920's Boll weevil epidemic in America led to the Duke of Bedford re-establishing the arsenic works as a philanthropic exercise in providing work locally. |
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