Botallack Mine

Overview

Botallack, its Crowns engine houses perched dramatically on the cliffs above the Atlantic, is one of the most photographed mining sites in Cornwall — and one of the most genuinely productive, with workings extending some 400 m out under the sea.

History

Documented mining at Botallack dates from the 1500s, when shafts were deliberately kept shallow to avoid the need to pump out seawater; the site may have been worked as early as the Roman or Bronze Age periods, though the evidence for this is unclear. The mine had a close call in 1835, when it was put up for sale and bought by the former Cornish wrestler Stephen Harvey James, who kept it running at a loss for two months — until a huge new copper lode was struck, yielding £44,000 profit and securing both his fortune and the mine's future. Over its working life from 1815 the mine produced roughly 14,500 tonnes of tin, 20,000 tonnes of copper and 1,500 tonnes of arsenic, alongside smaller quantities of cobalt, lead and silver; the mineral botallackite, a copper chloride mineral, was named after its discovery here in the 19th century. Purpose-built arsenic-refining chambers — the "arsenic labyrinth" — were constructed in 1906 to capture the poisonous fumes given off when calcining tin ore, drawing them through tunnels to a tall chimney stack. Falling tin and copper prices, driven by increasing world tin supply and falling American demand for tinplate, brought the mine to closure in 1895, though some accounts describe operations continuing in a reduced form until as late as 1914.

Geology

Botallack worked tin, copper and arsenic-bearing lodes on Cornwall's north coast near St Just, part of the same orefield as neighbouring Levant. The mineral botallackite was first identified here.

Workings

Workings reached at least 250 fathoms (about 500 m) below sea level, with the Botallack engine-shaft alone reaching 220 fathoms (1,320 ft); much of the deep workings extended out beneath the Atlantic. Ore was processed and calcined on site, with arsenic fumes from the calciner drawn through the 1906 "arsenic labyrinth" flues to a chimney stack.

Closure

The mine closed in 1895 as falling tin and copper prices made continued working uneconomic; some accounts describe reduced-scale operations continuing to as late as 1914, though the detail of this later period is less well documented.

What remains

The site is owned and managed by the National Trust and forms part of the Cornwall and West Devon Mining Landscape UNESCO World Heritage Site, inscribed in 2006.

Surviving structures include two engine houses in the cliffside Crowns section, the remains of two further engine houses on the slopes above, a count house, and the arsenic refining works and labyrinth at the cliff top.

Redevelopment

No major redevelopment has taken place; the site is preserved and open to visitors as a National Trust property and Scheduled Monument.

Abandoned workings can be dangerous — unstable ground, uncapped shafts, flooding and bad air are common even where a site looks safe from the surface. This entry describes history and general location only; it is not an access guide.

Recorded claims

Individual factual claims, each attached to the source(s) that support it below. Where sources disagree, both are kept.

• The mine is generally described as closing in 1895 on falling tin and copper prices; some secondary accounts instead describe operations continuing in reduced form to 1914. (disputed) ¹
• The mineral botallackite, a copper chloride, was first identified at Botallack in the 19th century and is named after the mine. ¹
• In 1835 a huge new copper lode was discovered at Botallack within two months of the mine being bought by Stephen Harvey James, yielding £44,000 profit and rescuing the mine from closure. ¹

Photographs & further reading

This page doesn't try to reproduce everything — these are the best original sources found for this mine.

Images

Sources

1. (secondary) Botallack Mine — Wikipedia
2. (secondary) The history of Botallack — National Trust