Blowing house at Hook Lake

Historic England's scheduling record (list entry 1002605) describes a tin mill in the upper Erme valley just north of the junction of Hook Lake and the River Erme. It is a rectangular drystone building 6.3 metres long by 3.8 metres wide inside, with walls up to 0.7 metres wide and 1.5 metres high. Inside, a section of narrower cross wall seems to be a later addition, and the entrance is in the south wall at its west end. It lies in the parish of Harford.

A large stone inside has a rectangular depression thought to be a mould stone, a long slot and two axle bearings on one edge. The mould stone suggests it worked as a blowing mill for smelting tin. A wheel pit up to 4.5 metres long, mostly filled with fallen stone, lies at the west end of the north side, and above it a leat embankment joins a long leat running back to the Erme. A nearby place name, Knackersmill Gulf, might mean the mill was also used as a stamping mill for crushing cassiterite.

The mill stands in an area full of tin streamworkings and other remains, some scheduled and some not.

Sources: Historic England list entry 1002605 (updated 11 November 2015), which cites Butler, Dartmoor Atlas of Antiquities, vol 4 (1993), and PastScape 441632.

• Period: Medieval
• Status: Scheduled monument (Historic England list entry 1002605)
• Grid reference: SX 6393 6509 (approximate, from the listing's coordinates)