Reasons for Designation
Approximately 10,000 lead industry sites are estimated to survive in England,
spanning nearly three millennia of mining history from the later Bronze Age
(c.1000 BC) until the present day, though before the Roman period it is likely
to have been on a small scale. Two hundred and fifty one lead industry sites,
representing approximately 2.5% of the estimated national archaeological
resource for the industry, have been identified as being of national
importance. This selection of nationally important monuments, compiled and
assessed through a comprehensive survey of the lead industry, is designed to
represent the industry's chronological depth, technological breadth and
regional diversity.
Ore hearth smelt mills were introduced in the 16th century and continued to
develop until the late 19th century. They were the normal type of lead smelter
until the 18th century, when they were partially replaced by the reverberatory
smelt mill. The ore hearth itself consisted of a low open hearth, in which
lead ore was mixed with fuel (initially dried wood, later a mixture of peat
and coal). An air blast was supplied by bellows, normally operated by a
waterwheel; more sophisticated arrangements were used at some 19th century
sites. The slags from the ore hearth still contained some lead. This was
extracted by resmelting the slags at a higher temperature using charcoal or
(later) coke fuel, normally in a separate slag hearth. This was typically
within the ore hearth smelt mill, though separate slag mills are known.
Early sites were typically small and simple buildings with one or two hearths,
whereas late 18th and 19th century smelt mills were often large complexes
containing several ore and slag hearths, roasting furnaces for preparing the
ore, refining furnaces for extracting silver from the lead by a process known
as cupellation, and reducing furnaces for recovering lead from the residue or
litharge produced by cupellation, together with sometimes complex systems of
flues, condensers and chimneys for recovering lead from the fumes given off by
the various hearths and furnaces. The ore hearth smelt mill site will also
contain fuel stores and other ancillary buildings.
Ore hearth smelt mills have existed in and near all the lead mining fields of
England, though late 18th and 19th century examples were virtually confined to
the Pennines from Yorkshire northwards (and surviving evidence is strongly
concentrated in North Yorkshire). It is believed that several hundred examples
existed nationally. The sample identified as meriting protection includes: all
sites with surviving evidence of hearths; sites with intact slag tips of
importance for understanding the development of smelting technology; all 16th-
17th century sites with appreciable standing structural remains; 16th-17th
century sites with well preserved earthwork remains; and a more selective
sample of 18th and 19th century sites to include the best surviving evidence
for smelt mill structures, and flue/condenser/chimney systems.
Providence smelt mill is thought to be the best preserved small single-hearth
smelt mill in the region, and represents a most unusual survival nationally.
The simple structure and small size of the mill, together with the remote and
undisturbed nature of the site, mean the survival of well preserved
archaeological remains in a compact area. The mill is further distinguished by
atypical features such as the short flue, and the arch which carries it over a
trackway.
The remains of the smelt mill building and the earthworks to its west will
retain important technological information on 18th century small-scale lead
smelting, the provision of power to the site, and the transportion of
processed lead from it, while nearby deposits of slag and ore processing
wastes will provide additional information on the efficiency of extraction.
The Greenhow area in which the monument lies is a landscape rich in the
remains of the lead mining industry from all periods, and the monument
contributes toward our understanding of this complex mining landscape.
Details
The monument lies on the north bank of the Brandstone Beck, approximately 250m
NNE of the Cock Hill and Sunnyside lead mines. It includes the ruined
structures, earthworks and buried remains of a small single ore-hearth smelt
mill.
The smelt mill building, situated immediately north of a modern trackway, is
9m by 11m, with walls standing to 1.8m in places. An internal wall with two
narrow archways, one blocked, divides the structure into chambers interpreted
as ore store and ore hearth. A flue extending from the north wall of the smelt
mill was formerly carried over a trackway by an arch, and still runs from the
smelt mill veering slightly to the east, for 20m. Masonry throughout is plain
and functional, consisting of roughly dressed and coursed sandstone.
Earthworks surviving to a height of 0.3m immediately west of the smelt mill
indicate the presence of a further chamber. One slag heap remains to the south
west of the mill. This and other deposits of process residues will retain
technological information about lead smelting and are thus included in the
scheduling. Buried features such as dressing floors will also survive in the
vicinity.
The smelt mill was built in the 1780s by the White family, who owned several
small mines, and the 1854 Ordnance Survey map of the area shows the mill
intact at this date.
MAP EXTRACT
The site of the monument is shown on the attached map extract.
