Arsenic mine and processing works known as Gawton Mine.
Reasons for Designation
Cornwall and West Devon, has been one of the major areas of non-ferrous metal mining in England. It is defined here as prospecting, extraction, ore processing and primary smelting/refining, and its more important and prolific products include copper, tin and arsenic, along with a range of other materials which occur in the same ore bodies. The development of steam power for pumping, winding and ore processing in the earlier 19th century saw a rapid increase in scale and depth of mine shafts and technological innovation of processing towards the end of the century. Arsenic extraction evolved rapidly during the 19th century, adding a further range of distinctive processing and refining components at some mines including the patented Brunton calciners which were brick covered rotating iron plates with a furnace beneath onto which crushed ore was placed and stirred. The more general calciner consisted of an of an iron brick lined cylinder which rotated over a furnace. From the kilns arsenic vapour was fed through lengthy flues usually uphill to a tall chimney designed to help disperse residual fumes. Following recovery from the flues the arsenic went to a refining furnace where the condensed vapour crystallized in tile-lined chambers. From here it was collected and ground to a powder. The South West became the world's main producer in the late 19th century. Arsenic was used in the glass industry, in making enamels, paints and insecticides. The arsenic mine and works known as Gawton Mine is considered to be the best, most complete surviving example of this type of mining, ore dressing, calcining and refining works in the country. The two Brunton calciners are a particularly rare survival.
This record was the subject of a minor enhancement on 18 November 2015. This record has been generated from an "old county number" (OCN) scheduling record. These are monuments that were not reviewed under the Monuments Protection Programme and are some of our oldest designation records.
This monument includes a 19th century arsenic mine and associated processing works situated on the southern bank of the River Tamar at Gawton. The monument survives as a group buildings and earthworks including: limekilns, a chimney stack and flue, a count house, washing and crushing plants, two Brunton calciners, a cooperage, dam, reservoir, engine house and chimney, a boiler house, smithy or manager’s house, refinery, quay, storage buildings and large areas of waste tips. The flue runs for several hundred metres up an extremely steep hillside and is well over 2m high in places with walls in excess of 0.7m wide. There is a tall, leaning, well preserved chimney. Falconer described it as ‘this prominent stack, whose pronounced slant is said to be due to the cement on the south side drying out before that of the north when it was built in the 1890s, terminates the longest and most impressive arsenic flue in the country ‘. The spoil heaps are a major feature in the landscape and are estimated to hold over 124,000 tons of material. To the west are the remains of the steam powered crushing, jigging and buddling plant with associated waste and a refinery which as a group are an important survival. The old quay was used to bring local limestone by barge from Plymouth to the limekilns, one being an early kiln with two later additions, which supplied lime for local agriculture. Gawton Mine worked arsenic from about 1846, although it had begun as a copper mine rather earlier when it worked using water power alone. However, interruptions in the water supply meant that the surface buildings were completely rebuilt in 1890 when the arsenic refinery was added. Although not totally successful in its own right this works together with nearby Devon Great Consols who took over this works in 1895, were the largest arsenic producers in the region. The works eventually closed in 1902.