HeritageGateway - Home
Site Map
Text size: A A A
You are here: Home > > > > Devon & Dartmoor HER Result
Devon & Dartmoor HERPrintable version | About Devon & Dartmoor HER | Visit Devon & Dartmoor HER online...

See important guidance on the use of this record.

If you have any comments or new information about this record, please email us.

HER Number:MDV5112
Name:Tin mill at Hook Lake to the east of the River Erme, Harford


Remains of a pre-1700 blowing or stamping mill at Stoney Brook . The structure is rectangular in plan with walls up to 1.5 metres high and a well-preserved wheel pit at the west end, with axle-bearing stone and well-defined, extensive leat.


Grid Reference:SX 639 650
Map Sheet:SX66NW
Admin AreaDartmoor National Park
Civil ParishHarford
DistrictSouth Hams
Ecclesiastical ParishHARFORD

Protected Status

Other References/Statuses

  • National Monuments Record: SX66NW26
  • National Record of the Historic Environment: 441632
  • Old DCC SMR Ref: SX66NW/32
  • Old SAM County Ref: 805

Monument Type(s) and Dates

  • BLOWING HOUSE (Constructed, Early Medieval to Early 20th Century - 1066 AD (Between) to 1901 AD (Between))
  • LEAT (Constructed, Early Medieval to Early 20th Century - 1066 AD (Between) to 1901 AD (Between))
  • STAMPING MILL (Constructed, Early Medieval to Early 20th Century - 1066 AD (Between) to 1901 AD (Between))
  • WATERMILL (Constructed, Early Medieval to Early 20th Century - 1066 AD (Between) to 1901 AD (Between))
  • WHEEL PIT (Constructed, Early Medieval to Early 20th Century - 1066 AD (Between) to 1901 AD (Between))

Full description

Kelly, T., 1866, Celtic remains on Dartmoor, 128 fig.4 (Article in Serial). SDV154696.

Ordnance Survey, 1880-1899, First Edition Ordnance 25 inch map (Cartographic). SDV336179.

Rectangular building with internal division shown on 19th century map.

Burnard, R., 1888 - 1889, On the Track of the 'Old Men', Dartmoor, 235 (Article in Serial). SDV154694.

Crossing, W., 1889-1890, Tin mill at Hook Lake, 217 (Article in Serial). SDV152718.

Burnard, R., 1890, The Antiquity of Mining on Dartmoor, 100 (Article in Serial). SDV152712.

Crossing, W., 1912 (1965), Crossing's Guide to Dartmoor, 396-9 (Monograph). SDV320981.

Worth, R. H., 1940, The Dartmoor Blowing House, 218, 249-50 (Article in Serial). SDV154693.

Tin mill at Hook Lake. The building measures internally 6.76 metres long by 3.81 metres wide at one end and 3.96 metres wide at the other. It is divided into two compartments by a cross wall, which appears to be of later date than the main walls. The walls vary in thickness from 610 millimetres to 762 millimetres. There is a raised bank to conduct the water to the wheel, the wheel pit is well preserved and the wheel may have been 2.591 metres in diameter and 457 millimetres brest. The mould stone has been broken or purposely split. The mould has two sample moulds, each about 76 millimetres by 51 millimetres, with another perfect cavity in the stone, which is not a mould but a recess to take the bearing of the water wheel. The two supposed sample moulds are really bearings for an iron axle, of about 51 millimetres diameter. One bearing is roughed out, the other polished by use. The other sinkage in the stone is a slot, 305 millimetres by 89 millimetres and 89 millimetres deep. May have taken the plummer-block of the water wheel.

Worth, R. H., 1941, Dartmoor: 1788 - 1808, 206 (Article in Serial). SDV160667.

Worth, R. H., 1953, Dartmoor, 298-9 Fig 88 and 89 (Monograph). SDV231148.

A building at Hook Lake, is divided into two compartments by a cross wall, which appears to be of later date than the main walls. A stone, formerly described as a mould-stone contains four cavities; a supposed 'mould', two circular depressions, one of which has been polished by use, and a foot long slot. The polished depression would appear to be a bearing for the iron axle of the water wheel. This building was probably first a blowing house and subsequently a knacking-mill. Immediately opposite Hook Lake is a valley called Knackersmill Gulf.

Harris, H., 1968, Industrial Archaeology of Dartmoor, 195 (Monograph). SDV149229.

There is a probable blowing house near the point where Hook Lake flows from Stony Bottom.

National Monuments Record, 1976, SX6365, 3 (Aerial Photograph). SDV144574.

Photograph taken on 22nd April 1976.

Hankin, C. F., 1977-1980, Harford Parish Checklist (Worksheet). SDV149931.

The south wall facing the stream, is very much ruined, but the other walls supported by natural banks are much better preserved. The wheelpit is probably not well preserved. The wall dividing the two compartments of the building is clearly seen but very ruinous in condition. The stones with the slots for the bearings of some machinery is still there.

Ordnance Survey Archaeology Division, 1978, SXNW26 (Ordnance Survey Archaeology Division Card). SDV249843.

(12/01/1978) The description and dimensions of this blowing house are as given by Worth (1953). The whole structure is in a very ruinous state.
Surveyed at 1:10 000 on PFD.

Greeves, T. A. P., 1981, List of Known Devon Tin Mills c1450 - c1750, No 38 (Report - non-specific). SDV319826.

Tin mill field evidence.

Robinson, R., 1983, List of Field Monument Warden Visits (Site Visit). SDV114314.

Site visited on 28th December 1982 and 19th January 1983.

Royal Commission on the Historical Monuments of England, 1985, Aerial Photograph Project (Dartmoor) - Dartmoor Pre-NMP (Cartographic). SDV319854.

Visible on aerial photograph and recorded.

Newman, P., 2018, Erme Valley Survey data (GIS and Excel spreadsheet) (Cartographic). SDV361913.

Building shown on survey.

Newman, P., 2018, The Upper Erme Valley, Dartmoor National Park, Devon: An Archaeological Survey, Appendix 1 (Report - Survey). SDV362921.

A ruined tin mill 18.5 metres east of the River Erme at Hook Lake. The building sits at the foot of the northern scarp of the Hook Lake streamworks (MDV 13179), just east of the point where it meets the Erme Valley streamworks. The rectangular structure has approximate internal dimensions of 6.9 metres by 3.9 metres with stone walls of between 0.6 and 0.8 metres thick. The northern wall is a revetment which reinforces the slope and survives to over 1 metre high. Other walls have tumbled and the interior is strewn with fallen stone. There is also a low north to south partition wall dividing the building into two. The entrance opening is currently obscured but likely to have been located near the south-west corner of the south wall. The wheelpit on the northern exterior is now filled with stone. A stone with worked indentations, including a fractured mould cavity, remains within the interior of the building. The building is partly disguised by bracken during the summer months. A clear though dry and silted earthwork leat can be traced from the bank just above the building, for 70 metres north-west where it meets another leat channel, of which it is a branch, traceable back to the source on the River Erme at SX63926541. No documentation has so far been unearthed to date this mill but a most likely date range for its construction and use would be the 16th or 17th century.

Various, 2018-2020, PALs Condition Recording forms, UE-18 (Worksheet). SDV362781.

(13/03/2019) Recorded by volunteer condition assessor. Condition assessed as good. Tucked into the bank formed by tin streaming as it cut into the landscape this monument appears to have suffered little change in the last ten years. Vegetation encroachment appears to have remained stable with a mixture of bracken, grass and moss.

Various, 2018-2020, PALs Condition Recording photographs (Photograph). SDV363073.

Photographs taken in March 2019.

Ordnance Survey, 2020, MasterMap 2020 (Cartographic). SDV363413.

'Blowing House (remains of)' shown on modern mapping.

Historic England, 2020, National Heritage List for England, 1002605 (National Heritage List for England). SDV363414.

The monument includes a tin mill situated in the upper Erme Valley just north of the confluence between the Hook Lake and River Erme. The tin mill survives as a rectangular drystone structure measuring 6.3 metres long by 3.8 metres wide internally with walls of up to 0.7 metres wide and 1.5 metres high. Inside there is a section of narrower cross walling which appears to be a later addition. The entrance is in the southern wall at its western end. Internally, there is a large stone which has a rectangular depression thought to be a mould stone, a long slot and two axle bearings on one edge. The presence of this mould stone suggests a possible function as a blowing mill for smelting tin. There is a wheel pit at the western end of the north side of the building which measures up to 4.5 metres in length and is largely in-filled with tumbled stone. Above this is a leat embankment which connects to a long leat leading back to the River Erme. A nearby place name of Knackersmill Gulf might also imply the tin mill was used as a stamping mill for crushing cassiterite.

Sources / Further Reading

SDV114314Site Visit: Robinson, R.. 1983. List of Field Monument Warden Visits.
SDV144574Aerial Photograph: National Monuments Record. 1976. SX6365. 3.
SDV149229Monograph: Harris, H.. 1968. Industrial Archaeology of Dartmoor. Industrial Archaeology of Dartmoor. A5 Hardback. 195.
SDV149931Worksheet: Hankin, C. F.. 1977-1980. Harford Parish Checklist. Parish Checklist. Digital.
SDV152712Article in Serial: Burnard, R.. 1890. The Antiquity of Mining on Dartmoor. Transactions of the Plymouth Institution and Devon and Cornwall Natural History Society. 11. Unknown. 100.
SDV152718Article in Serial: Crossing, W.. 1889-1890. Tin mill at Hook Lake. Western Antiquary. 9. 217.
SDV154693Article in Serial: Worth, R. H.. 1940. The Dartmoor Blowing House. Transactions of the Devonshire Association. 72. Paperback Volume. 218, 249-50.
SDV154694Article in Serial: Burnard, R.. 1888 - 1889. On the Track of the 'Old Men', Dartmoor. Transactions of the Plymouth Institute. 10. 235.
SDV154696Article in Serial: Kelly, T.. 1866. Celtic remains on Dartmoor. Transactions of the Devonshire Association. 1. 128 fig.4.
SDV160667Article in Serial: Worth, R. H.. 1941. Dartmoor: 1788 - 1808. Transactions of the Devonshire Association. 73. Unknown. 206.
SDV231148Monograph: Worth, R. H.. 1953. Dartmoor. Dartmoor. Hardback Volume. 298-9 Fig 88 and 89.
SDV249843Ordnance Survey Archaeology Division Card: Ordnance Survey Archaeology Division. 1978. SXNW26. Ordnance Survey Archaeology Division Card. Card Index.
SDV319826Report - non-specific: Greeves, T. A. P.. 1981. List of Known Devon Tin Mills c1450 - c1750. List of Known Devon Tin Mills c1450 - c1750. 35. Unknown. No 38.
SDV319854Cartographic: Royal Commission on the Historical Monuments of England. 1985. Aerial Photograph Project (Dartmoor) - Dartmoor Pre-NMP. Royal Commission on the Historical Monuments of England Aerial Photograph P. Cartographic.
SDV320981Monograph: Crossing, W.. 1912 (1965). Crossing's Guide to Dartmoor. Crossing's Guide to Dartmoor. Hardback Volume. 396-9.
SDV336179Cartographic: Ordnance Survey. 1880-1899. First Edition Ordnance 25 inch map. First Edition Ordnance Survey 25 inch Map. Map (Digital).
SDV361913Cartographic: Newman, P.. 2018. Erme Valley Survey data (GIS and Excel spreadsheet). GIS ShapeFile. Digital. [Mapped feature: #125295 ]
SDV362781Worksheet: Various. 2018-2020. PALs Condition Recording forms. PALs Condition Assessment Project Forms. Digital. UE-18.
SDV363073Photograph: Various. 2018-2020. PALs Condition Recording photographs. PALs Condition Assessment Project Forms. Digital.
SDV363413Cartographic: Ordnance Survey. 2020. MasterMap 2020. Ordnance Survey Digital Mapping. Digital.
SDV363414National Heritage List for England: Historic England. 2020. National Heritage List for England. Digital. 1002605.

Associated Monuments

MDV122885Related to: Dry leat channel above Hook Lake, Harford (Monument)
MDV28121Related to: Streamworks along the River Erme, Erme Plains, Harford (Monument)
MDV13179Related to: Streamworks at Hook Lake, Harford (Monument)

Associated Finds: none recorded

Associated Events

  • EDV8082 - Survey of the Upper Erme Valley

Date Last Edited:Jan 12 2022 2:45PM