Newsletter August 2015
Well, I feel I must apologise for the long delay in updating our website with all the news of our dig in the Lanyon area. As you can see by the photographs the first phase of the dig has now come to an end, though questions still require answers but we decided we were confident enough in our findings to make our first presentation at Landithy Hall in Madron on the 23rd June. We had a lovely evening and surprisingly we were able to present this quite technical subject, in a way everyone could understand and enjoy it.
For those of you who do not know, we are referring to our find of December last year when a solitary piece of pottery, dating from the medieval period gave us reason to sink test pits in a small walled in area. Alas this first pottery was uncovered by an industrious rabbit going about his business so cannot be used as dateable evidence but in our first pits we started to hit what was, without doubt, some kind of granite laid floor, and there laid atop the floor were pieces of 16th century pottery, authenticated by the Truro Museum. What must be pointed out here is that the ground being dug consisted of very heavy clays and slimes, too heavy for any outside material to be washed in over the centuries, and as we found out later any water at all makes the clays and slimes even heavier and more impenetrable. As further backing to this statement we sank other test pits all around the outside of the site and, indeed, cleared the water culvert which enters the site (long since dried up) and have found no other examples of this particular type of pottery anywhere. For those interested it was identified as North Devon ware.
As the dig proceeded it was clear that the whole site had been laid with granite and that there were raised areas, channels and much deeper stone pits and, what with the clays, it was soon becoming clear that we had a very early tin mill. We had never meant to clear the whole site but we soon realised that the only way to understand the site was to do just that...a very unfortunate call as it meant we would have to move several very large piles that we had previously created in order to uncover the whole picture and I have to say it was worth it. Six months down the line and, as you can see, we have the whole working floor and main channel of a tye house.
The water passed into the ruin from the top left hand corner, where there would have originally been a dam area measuring 31 inch by 31 inch and standing around 3ft. Here the water and gravels etc would have collected and one of the workers would have stirred the water in order to separate the tin crystals from the waste. Tin (cassiterite), being heavier than the waste and water, would have settled behind a lip in the floor (which we located) and the water would have run out over the top of the dam, on occasion as the tin stuff built up in the bottom the water would have been shut off and the dam area cleared onto the floor by shovel, for bagging. The water and waste running over the top of the dam would have carried on down the main channel, again depositing any trapped tin on the floor, whilst the water was moved out of the channel via a gully that was laid in the left lower side of the channel. We are certain that the lower end of the channel was sluiced to control the flow as remains and the layout bear evidence of this. The water then passes out of the main channel to the right, through the central gully, crossing the main floor. Again it would appear this was boxed with timber as we found lots of timber residue and rust. From here it passed under a walkway and into the settlement pit (see upper right of photograph) where, once again, the area was dammed and the water mixture allowed to build up to a specific height. Once it reached this height the dam would be flushed out leaving only the solids ready for more cleaning. In this ruin the water passed out via a culvert in the lower left of the photograph.
The only outline of such a site dated to this period can be found in a book called De Re Metallica, written by Agricola in 1568. For those interested I suggest you have a look but bear in mind that this was written concerning Austrian methods so a little adaptation is necessary, but as I am sure you will see, the similarities are too numerous for it to be discounted.
These similarities revealed themselves when we decided to carry out some reconstruction using only the hard evidence that remained undisturbed, these being the two timber slots in the top and sidewall and the slots in the channel floor, from which we dug remains of iron. The first timber we placed across the width of the channel, making sure that it sat level. Then we ran a timber along the length of the channel to intercept the first and lo and behold they matched perfectly, not just in coming together but when we stood back to appreciate it we realised they also followed the slope of the channel precisely as per Agricola. Then we placed sections of round pole into the slots located in the floor and found that they created the uprights necessary for a dam and, once again, they were in a perfect location to create the dam at the head of the channel. The floor itself was a wonder to behold when it was decided to wash it down for a photography session. We hurled buckets of water onto the floor and immediately noticed that the water did not leave the floor everywhere and anywhere but instead was concentrated in such a way that it ran into the settlement pit only. The workers had tipped (slightly) all the edge stones to push the water in that one direction...and here it was, still working!! We have measured the slope on all the floors and found the dip of the slope varies depending on how fast or slow you wished the water to run over the surface.... this construction was not just laid it was created with a lot of thought and skill and here we are, centuries later, and all the stonework is as good as when first laid.... how many modern constructions will fair that well?
Interestingly we have had Adam Sharpe of the Archaeological unit, Ainsley Cock of World Heritage, Barry Gamble, a consultant to World Heritage and Dr Tom Greeves of the Dartmoor Tin Mill Group visit the site and all have agreed that this is a very important site with no known site to compare it to. As a result we have been asked to present our findings at an International conference of tin milling in Tavistock next May. It has been great to find that these individuals are more than happy with how we are working the site as well as agree with a lot of our theories and the help they have offered us is very much appreciated.
This is a work in progress and shall probably stay such for some time in the future as we are finding other leads we need to follow in order to understand the full picture. At present we have moved outside of the ruin, following the water culvert in the hope that we shall find its true path, as this valley has many culverts, leats and millpools, all of which need placing in the order of appearance in history, if this is at all possible. A full survey of the valley is being carried out which, in itself, is answering a few questions.
A report has been written on this first part of the dig, complete with colour photographs and full explanations and is on sale for £5.00. If you would like a copy please contact us (see contacts page of this website) and place an order. We shall do further presentations this year and shall organize a visit to the site in the near future. We must ask though that if you wish to visit the site that you contact us to make arrangements and do not attempt to visit unaccompanied as this could upset the access granted to us by the landowners and tenant farmers.
We must thank those people that are helping us with our investigations such as Alasdair Neill of the Plymouth Caving Group for the surveying, the South Crofty team under Keith Russ and various members of the Dartmoor Tin Mills Group for their voluntary contribution. Stuart Emmett