Furze was harvested from heath land [or rough ground] and was once a primary source of domestic fuel for cooking and heating in west Cornwall. The management of furze in this way was part of an ancient and traditional method that ensured extensive grazing for livestock. The cutting of furze provided a varied mix of plant and grasses which thrived on this management. It was also used as an industrial fuel used in tin smelting and for burning in lime kilns.
Source [P. Dudley, Historic Environment Service
http://www.cornwall.gov.uk/index.cfm?articleid=28957]