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
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.
Feldon Smelt Mill is thought to have had a working life of around 150 years.
Since its abandonment in the 19th century, the site has reverted to grazing.
Buried archaeological deposits will survive providing evidence for the plan
and operation of the site, together with the surface remains of the layout of
the smeltmill complex and its associated slag tips. The archaeological
deposits are considered to include furnace bases and associated features,
together with process residues which will retain technological information.
Evidience of modifications to the smeltmill during its working life are also
thought to survive below the ground surface and, together with the information
retained in the slag heaps, the site affords a rare opportunity to study the
development of ore hearth technology from the late 17th to the 19th century.
The monument includes the ruins, earthworks and buried remains of the Feldon
Smelt Mill and lies on the left bank of the Feldon Burn, 2km south west of
Documentary records indicate that following the accession of Charles I, all
silver within 10 miles of Muggleswick was granted to the Duke of Buckingham.
Feldon Smelt Mill was built in the late 17th century, during the reign of
Charles II, to smelt this ore. In 1725 the lead mines within the Manor of
Muggleswick were acquired by the London Lead Company which also took over the
operation of the smeltmill, and they continued to operate the mill into the
Feldon Smelt Mill is an example of a medium sized simple ore hearth smeltmill
of the 18th to 19th century. The mill was powered by a waterwheel situated
within the smeltmill building, fed by a leat which zigzags down the hillside
to the south. The course of the leat, which is included within the scheduling,
crosses the line of a drystone field wall twice, the wall being supported by
large stone slabs over the leat. The smeltmill is visible as low wall footings
enclosing a broadly rectangular area measuring approximately 28m by 17m and
includes a 3m by 8m wheelpit. The remains of a lintelled opening is visible to
the west of the wheelpit and numerous pieces of metalwork, including the
remains of furnace plates, lie scattered about the site.
On the north east side of the mill the walls of a small building, measuring 8m
by 9m, stand to 1.4m high. The low wall footings on the south east side of the
smeltmill mark the site of a long rectangular three-roomed building, with
evidence of a blocked doorway at the south west corner. In addition, the
undisturbed slag tips to the north and west will contain significant
metallurgical evidence which will increase the understanding of the
development of the smelting technology employed at the site.
The monument also includes the remains of a flue and chimney. A short section
of double flue, approximately 10m long, remains largely intact near to the
mill and stands 2.75m high by 2m wide, with access points on either side of
the south west end measuring 0.75m high by 0.6m wide. The double flue has a
stopped end which is butted by the upper single flue. The single flue, which
is collapsed along its entire length, is 1m wide by 300m long and rises more
than 40m to a chimney on the hillslope above. The chimney, which is built of
well-coursed sandstone blocks with alternate long and short quoins
(cornerstones), is 2m square and survives to 1.5m high with a rectangular
opening in the north east side measuring 1.4m high by 1m wide.
All drystone field walls are excluded from the scheduling, although the ground
beneath them is included.
The site of the monument is shown on the attached map extract.
It includes a 2 metre boundary around the archaeological features,
considered to be essential for the monument's support and preservation.