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The Longstone Tinners’ Mill is a very ruinous rectangular structure which is located beneath the high water level of Burrator reservoir but is exposed in drought conditions. It is listed as a pre-1700 tin-mill and although very little is discernible there are two (probable) mouldstones still extant and a inscribed rock which may be of interest to the visitor.
The location of the Tinners’ Mill is at SX55988 68766. The black and white OS map is from the 1892-1914 with the inset being the modern OS map showing the location.
This annotated OS map dates from 1873-1888, just before the reservoir dams were constructed and the reservoir began to fill in 1898. The Tinners’ Mill is located quite close to the original Plymouth Leat Head Weir. The Plymouth Leat was completed in 1591 and it is recorded that a leat was in existence in 1623, and which was diverted from just downstream of the Head Weir to just upstream of it to supplement the Plymouth Leat (Ref: Water from the Moor by David J. Hawkings). Therefore it is possible that the Tinners’ Mill might have taken its water from this source? If the Tinners’ Mill didn’t take its water from this source, it would have most probably come from the Narrator Brook a little further to the north. The Longstone Mill Leat is very long and took its water from the Drizzlecombe Brook. This leat still feeds Ditsworthy Warren House and can be traced to Sheepstor village.
Site of the Tinners’ Mill with many squared off block an two upright (probable) mouldstones. In the Dartmoor HER it is recorded that: “A mouldstone lying in the top water level of the reservoir was rescued by the foreman and transferred to the grounds of Plymouth corporation on the north shore”. R.H. Worth in 1940, speculated that the transferred mouldstone came from this site.
Dr Tom Greeves records that tinners’ slag has been found here. He further records that there is possible documentary references (to a blowing house at Sheepstor) in 1680, 1719, 1730, 1751.
R.H Worth in 1940 (ref Transactions, The Dartmoor Blowing House, 224) records the remains of a blowing house at SX 561 688 (which is close to the authors NGR measurement). He further stated that before the reservoir was constructed a leat was clearly traceable. In the absence of access to the 1940 TDA record the author isn’t aware from which direction the leat came from.
Various squared off rocks at the site
One of the possible upright Mould Stones
This possible mould stone is the one nearest the shoreline
The second of the possible upright Mould Stones
This possible mould stone is the one furthest from the shoreline
View of the larger of the two mouldstones looking south west towards the Longstone peninsula.
An unusual “scooped” out rock can be found amongst the remains of the Tinners’ Mill
A short distance from the remains of the Tinners’ Mill is an inscribed rock. The author would like to acknowledge and thank Mark Fenlon, for supplying to the author a photograph of the location of this rock with its inscription, which was needed as the inscription was buried under several 10’s of centimetres of reservoir grit / sand.
Once the grit / sand alongside the rock had been cleared, an inscription was revealed, but wasn’t that discernible.
The author used some damp earth to enhance the inscription, which revealed and “IL” above “1740”. The 1740 might have possibly read 1790. That said, Dr Tom Greeves, recorded in his List of Known Devon Tin Mills c1450 – c1750 in 1981 that there is an “Inscribed stone on site is dated 1740”.
There may not be a direct link of course between the Tinners’ Mill and this inscribed rock. The author speculates that the “L” stands for Longstone. The author would be grateful if anyone knows what the “IL” stands for.
Close up of the inscription. Is the date “1740” or is it “1790” ?
Before leaving the site, the author buried the inscription and left the site as it had been found.