DR CAITLIN DE SILVEY
Geologist J. B. Hill visited the Carnon Valley in 1902 during a survey of geological deposits and associated industries in the region of Falmouth and Truro. Tin and copper production had dropped off precipitously and the industry was in decline, but the sides of the valley were still pocked and punctured by old excavations, and by adits that drained unwanted water from the network of deep mine shafts. The most extensive drainage system, the Great County Adit, discharged millions of gallons of water a day into the Carnon River through its outflow portal, the terminus of over 65 kilometres of snaking tunnels.
At Bissoe, just downstream of the portal, Hill came across a cluster of auxiliary industries that had developed to take advantage of the mining industry’s excess. Two arsenic factories operated near the Bissoe bridge, refining the crude arsenic from the mines for use in agriculture, pharmaceuticals and manufacturing. Hill wrote, “Ochre works exist in the same locality, which at the time of our survey in 1902 were said to have been in continuous operation for over 40 years. The oxide of iron carried in suspension, in the waters that discharge from the main adit into the Carnon stream, is caught in small pools, after which it is pulverized and washed. It is then dried into a fine brown ochre, in winter by fires, and in summer by the sun. The works are small, and there is no continuous market for the product.” Occasional buyers included the fishing industry, which combined the ochre with oil and coated sails with the mixture to protect them from seawater.
Mineral-rich water still flows from the Great County Adit’s exit portal near Twelveheads, carrying subterranean residues from the exposed surfaces of the old mines into the daylight world of the hard-used creek. The sediment that accumulates on its banks is a deep rusty red. A little over a century after Hill’s visit, Oliver scrambled down the bramble-choked banks of the river to scoop up a sample of sludge. He brought it back to his studio, where he spread it on glass plates to dry in the sun. He then ground the grain into a finer dust with a mortar and pestle, and mulled the powder in linseed oil. The resulting ochre pigment colours the words you are reading. Inadvertently, Oliver replicated almost exactly the process that Bissoe’s ochre works had used to transform mining waste into practical matter.
The pigment carries the traces of its origins. An elemental analysis shows high concentrations of arsenic and other heavy metals. Boats with ochre-red sails still ply the River Fal downstream, although the traditional fisheries are under threat from the accumulated effects of post-industrial and contemporary contamination. The exchange continues—earth elements suspended and then seized for our purposes, spinning out unintended effects, spilling into a creek, onto a page.
Text commissioned for the publication Natural Alchemy, 2014. The project was a collaboration between Dr. Chris Bryan of the University of Exeter’s Environment and Sustainability Institute (ESI) and artist Oliver Raymond-Barker. It is part of the Creative Exchange Program supported by the ESI and Falmouth University’s Research in Art, Nature and the Environment (RANE).
All text copyright the author.