Monument record MDR7534 - Barbrook slag mill, Blackstone Edge, Curbar

Slag Mill on Bar Brook, of late 18th century-early 19th century date. Water powered site, with remains of waterworks and buildings (1) Farey, in 1811, listed a slag mill in possession of Thomas and John Barker. (2) The lead mill, which lies in an area of wooded gritstone boulders on the north bank of the Bar Brook, has been designated a scheduled monument. It consists of the remains of a 17th-18th century smelt mill. The core of the site consists of a ruined two cell building lying east-west with remains of a chimney in the west wall. The interior of this building is largely obscured by rubble. To the east of this lies a dam which has been breached but is largely intact. The east boundary of the scheduled area is drawn to include the western parts of the access track and leat and a bridge where they cross each other, but excludes the eastern parts of both features, which are poorly preserved. To the north of the building, a hollow way leads to the north-west and a small building lies beside this. To the south of the building, fragments of associated walling extend to the Bar Brook. The mill was built in 1618 and closed around 1770. A gritstone mould for casting pigs of lead is recorded as having come from the ruins, but it is not now visible. On the north side of Bar Brook, downstream from Curbar Crossroads, are the particularly interesting remains of two mills once used to smelt lead ore and lead slags. The remains of the slag mill lie about 300m downstream of the upper mill [see HER 1302 for the upper mill], amongst rough ground in dense birch woodland. This was already abandoned by 1835 when the area was first mapped. The late 1870s detailed recording by the Ordnance Survey resulted in only a partial depiction of the ruins. This mill has previously been interpreted as the slag mill for a cupola built in the 18th century further down the Barbrook valley [see SMR 1349 for the cupola]. This is uncertain, as the site, which has extensive ruins, is linked by a trackway and leat with the mill upstream but there are no tracks running downstream towards the site of the cupola. It is more likely, therefore, that the ruins represent a slag works associated with the upstream 17th/18th century ore hearth smelting site rather than with the cupola. Its date of construction is currently unknown, although the fact that the buildings are of stone suggests an 18th century date rather than anything earlier. The ruins that exist north of the stream are of particular interest as a rare archaeological survival of a slag works. A narrow leat leads to a narrow and now dry header pond, embanked on the downslope side. Immediately beyond the lower end of the pond are the ruins of the main smelting building. This is a long rectangular structure with the lower courses of walls intact but with much obscured by collapse rubble, particularly in the building's interior. It was terraced into the slope and, given the lack of an obvious alternative site, the waterwheel for bellows appears to have been in the interior. A dividing wall part-way along, with a low opening through it, may have separated a room that housed the bellows from the furnace itself. At the western end of the building is the circular base of what may well be a chimney built into the end wall. On the downslope side of building, there appear to have been open-fronted offshuts, although no dividing wall from the main rooms is visible. A stone casting mould for pigs photographed on site in 1941-42 was not found in 2008. The track from the upstream smelting mill enters the site to the side of the header pond and led to the downslope side of the main building. From here it ran around the western end and rose to the upslope side where there was a small yard. Here there are patches of bare ground, presumably because of comminuted lead in the soil, where cinders from the smelting hearth are exposed. On the upslope side of the yard there are the ruins of a second small building, presumably a store shed or workshop. Another small structure with retaining wall, of unknown purpose, lies beyond the opposite side of the main building, midway between this and the stream below. From the upslope yard another access track leads diagonally north-westwards up the steep slope. (3) The site was surveyed in 2010/2011. Features included the relatively well-preserved remains of a sandstone mill building with three identifiable rooms, a leat and the remains of a raised platform, probably a former mill dam. The walls of the building survive to a height of 1.5m, but are threatened by tree root damage from trees growing within the walls. (4) Foundation walls of former smelt site are still visible. Evidence of coal, coke and slag, Foundations of former mill building also present. Latterly a corn mill but possibly related to the lead smelt at an earlier date. Weir, leet and dam, and stone bridge across Barbrook. (5)