Small scale industrial site related to the Dye mill in Thurlstone (HSY6134). Now reused as a residential property. A mordant is required to fix dyes so they are light fast and don’t fade on washing. This mordant was produced on this site. Iron pyrites was exposed to air so that ferrous sulphate (copperas) was formed through oxidation. This was then boiled and cooled to crystallise the copperas. This process smells so was done away from the settlement area on a hillside. (Nicholson 2001,80). This area was unenclosed land until the Thurlstone enclosure act in 1816 (date English 1985). There is no legibility of this unenclosed landscape.