We lived and worked in the Luxulyan Valley in Cornwall for over 35 years, my work involved maintaining waterways for Hydro Projects and gave me free range to explore over 500 acres od mineral rich ground much of which still remains unrecorded.
The area around Blowing House is steeped in history, many of the items we have excavated point to its use as far back as the 13th century when the Monks of Tywardreath worked a corn mill on the site at Ponts Mill.
The industrial archaeology remaining from the days of the well known Joseph Treffry 1782-1850 and his leats once providing power to Fowey Consols copper mine still survive today, the famous Treffry viaduct bridging the higher levels of the valley stands as a lasting monument to a man whose drive and genious once made him the largest employer in cornwall.
This mortar stone, one of three, would have been used to grind the cassiterite allowing it to be freed from its matrix, it was discovered about three feet down below the floor which was our kitchen, also found were many other items including a lot of clinker like material that we later discovered was tin slag from the ancient furnace which must have been in close vicinity .
These three items were also pulled out from under various parts of the building during renovation, the odd shape of the stone tin ingot mould allowed it to be dated by experts to the early medieval period.
The long stone slab which has longitudal scrape marks along its length is thought to be that which was placed in to the end of a tin trough, the marks being the constant scraping by a tool for removing slag and detritus.The pestle shaped tool is self explanatory.
In January 2017 we had collected and smelted enough cassiterite from the property to at last cast an ingot in to the original stone mold, care was taken to reproduce the technique of using a part burnt wood stick pushed through the molten tin as the ancients would have done to leave a hole that would enable the ingots to be tied in pairs for transport on the back of a pack mule or similar.
We are pleased with the finished ingot which weighs over 12 lbs.
A Tin Candle.
These were formed by the slow leak of pure molten tin dripping from the bottom of the stone smelting hearth, in much the same way that wax from a candle forms similar shapes as it melts away and runs down the candlestick holder.
If they were found by the smelter then of course they would be thrown back in to the pot but occaisionally they escaped notice and were found centurys later buried in protective floor sand.
The four ingots shown here were recently recovered from an early medieval shipwreck off of the Aeolian Islands and bear a striking similarity in shape and form to those that would have been produced from our stone mould from the Luxulyan Valley.
The holes in the ingots were produced by piercing them with a wooden stick while the tin was still in a semi molten state and would have been used to rope them together for transport over the back of pack mule or similar.