ABSTRACT
Cosgarne Common is a ridge extending east from the elevated granite outcrop known as Carn Marth. It is bounded on the north side by the Wheal Maid Valley and Stream and on the south by the Hicks Mill Stream, the waters of both derived mainly from Carn Marth. Cosgarne Common was divided into two parts, east and west, with slightly different Lords, usually four in all, with Beauchamp having an interest in the western part. At Trevince an arsenic works relied mainly on the halvans (discarded material on waste heaps) for ore and at East Ale and Cakes the Gwennap United company set up a steam-powered plant for retreatment of tips for tin and arsenic in 1895, but this lasted in operation only a year or so. Growth of vegetation and destruction from other causes severely limits what can be seen today.
