Details

The monument includes a tin blowing mill situated at the foot of a steep 3m
high scarp adjacent to the North Teign river. The mill building is of drystone
construction with the wall standing up to 0.8m high. The interior of the mill
measures 13.6m by up to 3.5m and access to it was through a clearly mill, two
edge set stones represent the site of the furnace, in which the black tin
(cassiterite) was smelted. A hollow adjacent to the northern wall denotes the
position of the wheelpit in which a wheel powered by water operated the
furnace bellows. Molten tin from the furnace was ladled into a large mould
stone, containing two separate troughs which stands next to the furnace. A
second broken mould stone lies within the entrance. A 5.5m long by 2.3m wide
rectangular structure is attached to the south eastern end of the mill
building. This is defined by a rubble wall of varying height and width
standing up to 1.2m high.
In the area south of the mill there is a series of earthworks, some of which
are the result of earlier streamworking, but others may relate to dressing and
washing activities. Beyond these earthworks and adjacent to the river is a
drystone wall of 19th century date. Built into the top of this, a broken mould
stone and mortar stone are clearly visible. These features are included in the
scheduling

MAP EXTRACT
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.

Source: Historic England

Reasons for Scheduling

Dartmoor is the largest expanse of open moorland in southern Britain and,
because of exceptional conditions of preservation, it is also one of the most
complete examples of an upland relict landscape in the whole country. The
great wealth and diversity of archaeological remains provide direct evidence
for human exploitation of the Moor from the early prehistoric period onwards.
The well-preserved and often visible relationship between settlement sites,
major land boundaries, trackways, ceremonial and funerary monuments as well as
later industrial remains, gives significant insights into successive changes
in the pattern of land use through time.
Blowing mills (also known as blowing houses) survive as rectangular drystone
buildings served by one or more leats and are characterised by the presence of
granite blocks with moulds cut into them - bevelled rectangular troughs known
as mould stones - and on occasion by the square or rectangular stone built
base of the furnace itself. During the medieval and early post-medieval
period, black tin (cassiterite) extracted from streamworks and mines was taken
to blowing mills to be smelted. At the blowing mill the cassiterite may have
been washed a final time before being put into the furnace together with
charcoal. To smelt tin the temperature within the furnace had to reach 1150
degrees C. This was achieved by blowing air through the furnace using water
powered bellows. Once the tin had become molten, it flowed from the furnace
into a float stone and was ladled into the mould stone, in which it cooled to
form an ingot of white tin. The original number of blowing mills on Dartmoor
is unknown, but at least 26 are believed to survive, whilst a further 41 are
known only from stray finds and documentary sources. All examples with a
clearly identifiable surviving structure are therefore considered to be of
national importance.

The blowing mill 260m south east of Teignhead Farm survives well and is one of
only seven examples known to contain a furnace. Important information
concerning tin smelting technology survives within and around this building.
The unusual mould stones containing two troughs and the particularly large
furnace block are of special interest.

Source: Historic England

Sources

Other
Devon County Sites and Monuments Register, SX68SW46, (1995)
MPP fieldwork by S. Gerrard, (1999)

Source: Historic England