Lead‐smelting site on the Pennines and the Mendips dating from the period before the adoption of bellows‐blown hearths in the 16th century. The sites, which occupied windy escarpments, are often commemorated by the place‐name Bole Hill, but remains are difficult to identify. The bole consisted of a stone‐walled enclosure up to 5 or 6 yards in diameter, open on the side of the prevailing wind. The ore was stacked in the hearth and covered with brushwood and thicker wood. The molten lead was directed into a pig‐mould. See David Kiernan, The Derbyshire Lead Industry in the Sixteenth Century (1988).