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.
Medieval lead smelters include a range of features known from field or
documentary evidence. The commonest type is the bole or bolehill, a wind-blown
smelting fire located on an exposed hilltop or crest. This consisted of a
rectangular or circular stone structure, open on one side, within which a
large fire was constructed using large blocks of wood at the base and smaller
wood interleaved with ore above. Boles used the wind to provide draught and
were located on exposed summits or ridges, normally facing south west. The
molten lead was run out by channels on the upwind side into a casting pit or
area. The slags produced by the bole retained considerable quantities of lead.
Some of this could be extracted by crushing and washing the slags and the
remainder could be recovered by resmelting the slag in a smaller enclosed
hearth (the slag hearth or 'blackwork oven') using charcoal fuel and an air
blast normally supplied by hand or foot operated bellows; the resulting black
glassy slag is distinct from the grey or yellow slag produced by the bole
itself.
The bole and associated features were in use from at least the 12th to the
late 16th centuries. They are important as the main form of medieval lead
smelting technology, differing markedly from the smelting technology of other
metals. Boles are found on exposed sites in and around the Pennine lead mining
fields; there is also historical evidence for their existence in Shropshire,
but they are not known to have existed in the Mendip or south west England
mining areas. It is likely that around 200 bole sites existed, with smaller
numbers of slag washing sites (sometimes in separate locations from the bole).
The majority of sites are known from place name evidence only; scatters of
slag or visibly contaminated ground are unusual, and sites retaining
informative slag distributions, intact tips, or visible structural or
earthwork features are very rare. All sites with informative slag
distributions, intact tips, or visible structural or earthwork features are
therefore considered to merit protection. It is known that other types of lead
smelter were used in the medieval period. There is documentary evidence for
smelter types known as the 'furnace' in Devon and the Mendips, 'hutt' in
Devon, and 'smelt mill' in North Yorkshire. On the Mendips, most smelting was
undertaken at four central washing and smelting places known as 'mineries',
probably using small open hearths blown by foot powered bellows. There is also
field evidence for an enclosed smelting furnace (from the Isle of Man) and a
range of sites identified by scatters of slag (from County Durham). These
field site types cannot yet be fully correlated to the documented site types,
and are a priority for future research. Due to their rarity, all non-bole
medieval lead smelting sites retaining informative slag distributions, intact
tips, or visible structural or earthwork features are considered to merit
protection.
The Ramsley Moor monument forms an intact and undisturbed complex of an
unusual type with no known parallels of similar quality, and retaining a good
diversity of features. These include visible earthworks, intact slag tips, and
slag distributions over a wide area, all of which are unusual survivals on
sites of this early date. It has enhanced amenity value due to its location on
National Park property, and within a Site of Special Scientific Interest. The
site forms a major resource for the study of late medieval lead smelting
technology.
Details
The smelting site on Ramsley Moor is a medieval lead production site of
unusual character.
The monument lies along the west bank of a headwater of Millthorpe Brook, and
is traversed by a small leat originating from this stream at the south end of
the site and contouring northwards along the slope of the shallow valley. The
majority of visible features are linear earthwork mounds and spreads of broken
lead slag, occupying the area between the leat and the stream. Other earthwork
features are visible, including one interpreted as a wheelpit.
The monument is believed to be of late medieval date, and to represent an area
where slags from a nearby bole lead smelter were broken, washed, and resmelted
to extract the remaining lead.
MAP EXTRACT
The site of the monument is shown on the attached map extract.
