In Medieval times sliver-bearing ores were operated for a long period of time by the Crown on the Bere Ferrers peninsula. Not like current activity in other non-ferrous mining lands these were deep shaft mines functioning a rich but off limits resource. Not able to move to more available sources of ore, they used the most excellent industrial practice in drainage and smelting to keep up production. There is an extraordinary endurance of the field proof for mining technology from that time period. Providing a special corporal link with advances in drainage techniques in the mid 15th century.
Silver bearing ores have been operated on the Bere Ferrers or Birland peninsula, for almost six-hundred years. By the center of the 19th century there were at the most a dozen mines, some combined into bigger setts. The greater part of which operated silver-lead deposits found in north-south crosscourses. Two of those crosscourses, at South Hooe and Cleave proved specifically rich even as another to the east, north of Lopwell, was of only marginal trade and industry value.
Working of silver-bearing ores in the medieval times was in the hands of the Crown which held the privilege on all valuable metals plus copper and tin. At first the mines at Bere Ferrers were worked directly by the Crown but after 1350 they were decided on lease to outside interests, with the Crown retaining a royalty and right of pre-emption on the manufacture. The miners didn't even hold any of the rights enjoyed by the tinners of Devon and Cornwall or lead miners on Mendip and elsewhere.
If required they were forced into service and worked under the direct manage of Crown officers or the resident. An original lack of enough local knowledge in mining and smelting meant employees from places as far as North Wales, the Derbyshire Peak, Mendip, the Forest of Dean, and Cornwall was assembled in south Devon, being sure to bring with them skills suited to less difficult ore deposits.
New mines were opened up in the mid Wales in the late 16th century. Productivity peaked in the early years of 1297 and 1306, but even then hardly at a little over 23,000 ozs per annum. Regular production was about a tenth of that outline. Nevertheless, the command for silver was such that the mines remained at the head of industrial advances through and through the medieval time period.
After being open for a few years the Bere Miners were having a lot of problems with drainage. This made draining in the winter months a BIG problem. After that Galleries added to allow the free drainage of water to top or surface.
Towards the middle of the 15th century the workings were so deep that soon enough drainage was a problem again. Another problem was caused by the higher cost and shortage of workers brought about by an expanded stage of population decline. With no structure of power broadcast available it was necessary to bring the power source of water in the mine at the shaft head. That entailed a watercourse that was 16 kilometers long tapping tributaries of the River Lumburn.
The route can be found mainly on the steep west bank of the Tavy where the line had been cut through SOLID rock! A special physical link with the opening of modern technology in the later years of the medieval period.
The Ore Processing
The preparation, smelting and cleansing required processing the silver-bearing ores were a mixed together process at the Bere Ferrers mining field. In the first few years of processing in the later years of the 13th century. Production was controlled on the wood being fired, and wind blown 'bole' smelting, technique brought from the lead mining areas of the northern part of England.
However the bole was not capable of professionally smelting all the ore mined and was soon increased by charcoal fired, bellows blown furnaces created through a period of testing. Transfer by horse and by river played a very important role in the processing steps. Ore would be moved from the mines to the cleansing sites where waste was removed by simple gravitational parting. From there it was taken to one of a hundred smelting sites. Residues from smelting were taken away for crushing and washing to take away or separate the waste. The parts still containing lead and silver were then re-smelted in the heating system. Then, the smelted lead was moved from place to place to finish the process.
Working during the early years of modern times appears to have been concentrated at Buttspill, on the crosscourse north of the medieval mechanism, where a 'silver mine' was active in the early 1690's. However, much of the ground that was processed during the medieval time period was re-evaluated during the late time periods of the 18th and 19th centuries when, with the arrival of the new powerful steam pumping engines. The Workers were able to get to new ground below the medieval line limits.
END OF MINING
The best surviving evidence of medieval mining is to be found far away from the where the mines were located. In Blackmoorham woods, and Shillamill where cuttings and tunnels mark the course of the middle time period of the 15th century.