…hardly a patch of Cornwall was not touched by copper mining
In appendix IV of D.B. Barton’s A History of Copper Mining in Cornwall and Devon (1961) the author presents a table of copper ore and copper production by each parish in Cornwall and west Devon between 1815 and 1905. It remains the classic work on Cornish copper mining.
Barton compiled it from statistics published in the Memoirs of the Geological Survey on Copper Ores of Cornwall and Devon. I have taken the liberty to transcribe the table and reproduce it here and compile a bar graph to illustrate the data and allow comparison. I intend to map this data too for a more visual representation of Cornish copper producing areas. The results may surprise you.
The principles of mining economics
This 90-year period saw incredible ups and downs for the Cornish copper industry. Much of it was inextricably linked to the fortunes of smelting firms, most of which were based in the Lower Swansea Valley. Smelters dictated prices during this time and mine prospecting was closely linked with booms in the price of copper metal.
When domestic and global demand was high, the price rocketed, and when that demand disappeared so did many mining operations. If the price dropped so low that it was uneconomical to keep the mine open, it closed, the machinery that stopped it flooding taken away and then left derelict. Only a sharp upturn in the copper metal price balanced with the promise of a good yield would in certain circumstances persuade entrepreneurs to reopen closed mines. After nearly twenty years the global demand for Indium (due to rapid growth in mobile phone manufacture), for example, and an upturn in the price of other metallic minerals has seen small-scale mining operations return to Cornwall such as at South Crofty in Pool, near Redruth.
Mines also came and went depending on their output. Sometimes the yields from mines exceeded expectations, at other times they were disappointing. The amount of metal that can be extracted from its ore varies greatly, often as low as 1-2%. Only the price of the metal dicated whether it was economically viable to process such a large quantity of ore for such a small amount of metal (the very different type of ore and extraction techniques at Mynydd Parys on Anglesey broke this rule in the 1780s). The deeper the operation, the more water had to be pumped out (the job of the beam engines housed in the engine houses that are icons in the Cornish landscape) and so this too impacted on economic viability.
The price of transporting the fuel, coal, for driving engines and furnaces also affected the viability of a mine site. The ability of the mine to efficiently dress the ore on site (crushing and initial roasting or calcining to remove impurities and provide more concentrated metallic ore) before it went to market became an increasingly important factor in the price a mine could demand for its product. Many copper mines continued as tin mines when copper-bearing lodes were exhausted. Minerals such as bismuth, antimony, wolfram and arsenic could also see copper mines adapt their operations to exploit more profitable products.
This is a very rough sketch of the factors which impacted on why mines were opened and closed but it gives a useful context for the data presented below.
Caution: I have not followed up the sources used to generate these statistics. While absolute accuracy can never be guaranteed, taken as a whole this information paints an accurate picture of the range and yield of copper-producing areas in the nineteenth century.
Cornish and Devonian copper ore and copper production by parish
|Parish||Copper Ore (tons)||Copper (tons)|
|St Stephen in Brannel||75||5|
The richest square mile in Europe
The statistics and graphs clearly illustrate the evidence behind the claim that Gwennap parish was the richest square mile in the ‘Old World’ (i.e. Europe). The intensity of mining activity and output in Gwennap (highlighted red), especially when taken with that of neighbouring Redruth, Illogan and Camborne saw peak production in the 1830s and 1840s. The principal copper producing mines in Gwennap parish were Consolidated and United mines and these were exploited for copper well before these and comparable statistics were generated. However, from 1845 the discovery of vast reserves at Devon Great Consols shifted the major centre of copper production from west Cornwall to the Tavistock area of west Devon.
Mighty Fowey Conols
What many people do not know, and many mining historians and industrial heritage interpreters seem little of, is the huge contribution of Fowey Consols to Cornish copper production. From 1822 to 1867 Fowey Consols, situated in the mid-Cornwall parish of St Blazey with related operations in neighbouring Tywardreath (highlighted blue), produced almost 683,300 tons of copper ore (56,910 tons of metal), half that of Gwennap. Fowey Consols was Cornwall and Devon’s fourth most productive copper mine of all time.
I have not analysed this parish-based information to see if any Cornish parishes are not present in these statistics. But it is safe to say that hardly a patch of Cornwall was not touched by copper mining at one point or another, even the comparatively tiny operations in Wadebridge (highlighted green) which only raised 20 tons of ore for 5 tons of metal but even more optimistic were the mines of St Stephen in Brannel, better known as China Clay country, raising 75 tons of ore for only two tons of copper.
Copper probably defined more areas of industrial Cornwall than did tin or any other enterprise. Because Cornwall’s tin industry persisted for longer than its copper industry, and because of the particularity of tin to Cornwall and how it was dealt with (for example tin was smelted in Cornwall unlike copper which was shipped to South Wales), copper has become somewhat of a neglected subject of Cornish industry and heritage. It is often acknowledged in general terms in displays and guidebooks but seldom explored in any detail. I am hoping that my project on British copper will help revise our understanding of Cornish copper and its impact on the economy and material culture.