Cohort stands in what is known as The Stennack valley, with the main road outside the front entrance called The Stennack. When the Romans came to Cornwall in 43 A.D., they brought their language of Latin. The Latin name for tin is stannum from which comes the chemical symbol for tin: Sn. The Cornish word for ‘tin’ is ‘sten’ and as this area had been mined for centuries this gave rise to the name ‘Stennack’ which means ‘tin place’ or ‘tin bearing ground’
In its heyday there were 19 mines operating in St Ives. The nearest ones to the St Ives Wesley Methodist Chapel being Pednolva mine (or North Wheal Providence now the Pednolva Hotel), Ayr Mine (or Wheal Ayr) and Trenwith mine (or Wheal Trenwith)whose operations covered the Stennack valley. ‘Wheal’ means ‘place of work’ in Cornish.
Wheal Trenwith was located on the opposite of the valley to Cohort on the spot where the leisure centre and Trenwith car park now stands. Wheal Trenwith mine ran under this building as far as Royal Square behind us.
Wheal Trenwith was probably running from early 1800’s. Earliest documentation mentioning this mine is in the 2nd vol St Ives Corporations ‘Booke of Recorde (1638 – 1838)’. Wheal Trenwith had a rocky history, opening and closing as a tin and copper mine until ceasing in 1856, then after a 50 year gap the mine was brought back into life in 1908 before abruptly closing for good in 1917.
Wheal Trenwith is a mine which enjoys a reputation disproportionate to its size.
For most of its history copper and tin were mined at Wheal Trenwith. As with any other mine, over decades Wheal Trenwith created large amounts of waste. The mine raised large quantities of a black substance which was mistakenly took for black copper ore – a common waste product of tin mines.
However, in 1843 the Cornish geologist William Heawood made further inspection of this ‘black copper ore’ and found within it pitchblende – a radioactive, uranium-rich ore. Uranium had been discovered at Wheal Trenwith!
This remarkable find was put to the miners at that time who rejected the idea of excavating uranium for commercial sale. This was probably one of the largest commercial mistakes made by the miners – though logical due to the limited understanding of the substance at this time.
Because the qualities of pitchblende and uranium were then unknown and being regarded as little more than a curiosity, huge quantities of this (now valuable) ore was discarded into The Burrows (the hillside) and the local landscape; broken down and used to repair streets, walls and roads.
So whilst it was said that London streets were paved with gold, it could be said that St Ives is paved with uranium which became a much more valuable mineral. So even now if you take a Geiger counter around some of the streets and paths of St Ives, you will find your geiger counter becomes rather excited. You can check out videos on YouTube demonstrating this.
After closing as a tin mine in 1856 and lying idle for more than 50 years, Wheal Trenwith was reopened in 1908 as a uranium (and radium) mine under the control of the German-owned British Radium company.
The first person who appreciated the Wheal Trenwith pitchblende (uranium-ore) was Edmund Schitt. In 1908 he sent samples of the St Ives pitchblende to Marie Curie in Paris to inspect and use in her experiments. From this she also confirmed the presence of the highly radioactive and dangerous element radium, a mineral which in trace amounts are found in uranium-ore.
There was lots of interest in uranium and radium in the early part of the twentieth century once its properties were better understood. Wheal Trenwith produced some of the purest radium in the world and was one of the only producers of pitchblende in the UK.
Between 1911-1917, 694 tons of uranium ore were produced, mainly from dump material, although small, scattered, patches occurred underground in thin films in joints.
At this time Germany was ahead in terms of medical science and in 1913 bought the entire next 4-year output of uranium from Wheal Trenwith.
When WWI broke out a year later this contract was annulled. Wheal Trenwith approached the UK Government to purchase their radium, but they refused instead buying sub-standard radium from the US. Soon after the mine closed for good in 1917.
St Ives reputation as a uranium hotspot didn’t diminish with time. In 1945 it was reported that holiday makers to St Ives were still picking up small stones as souvenirs confident that they contained uranium and one enterprising local man sold these stones at 6p a piece and gave the money to the local hospital.
St Ives long had a reputation for its ‘healing water’. At the time the source of the towns water came from a spring which travelled through Wheal Trenwith. With the water travelling through a uranium mine it was later understood to be laced with radium, which at this time was believed to have considerable health benefits.
In this early part of the twentieth century the dangers of radioactivity weren’t appreciated. In fact, there was such enthusiasm for the beneficial effects of radium that at one point The British Radium Company put forward proposals to turn the Great Western Railway owned Tregenna Castle Hotel in St Ives into a Cornish Radium spa – utilising the supposed curative properties of the water.
Edmund Schitt, pitched a scheme to pump water from Wheal Trenwith to Tregenna Castle. The negative effects of radium were unknown at this point, and so luckily the scheme was later abandoned due to the death of his wife.
The Trenwith mine spring continued to be the principal water supply for a large part of St Ives for many years, being used without any treatment. However further health and safety legislation in the 1970’s probably contributed a to a more cautious approach and it was decided that this water source was no longer appropriate.
In late 1870’s tin mining in Cornwall collapsed when cheaper tin, from the Far East, flooded the world market and 90% of Cornish mines lost all value overnight. At this time the fishing industry was also in decline and holiday makers had yet to discover Cornwall. This hit Cornwall very hard with mass unemployment. Cornish miners could emigrate or starve. Many miners emigrated to the newly emerging mining areas such as Australia, South Africa and the Amercias. By 1890’s mining was virtually dead in the St Ives area, and by 1922 all mines in St Ives had disappeared permanently. At its height Cornwall produced 2/5th of the worlds tin; 300 mines employed 50,000 people, pulling 10,000 tons of tin out each year.
“Cornish lads are fishermen and Cornish lads are miners too. / But when the fish and tin are gone, what are the Cornish boys to do?” Lyrics from a Cornish folk group later graffiti’d on boundry wall of South Croft mine – the last Cornish mine to close in 1998