Herland Mine

Overview

Herland, a modest-sized copper mine near Gwinear, punched far above its weight in the history of steam power — hosting one of Cornwall's early Newcomen-type pumping engines in the 1720s and, seventy years later, the largest single-acting Boulton & Watt engine ever erected in the county.

History

Herland was worked for copper, alongside a notable yield of native silver, from at least 1726, when a 70-inch Newcomen-type pumping engine was already at work keeping the mine's workings, by then around 120 fathoms deep, clear of water. The mine worked intermittently over the following century, with recorded periods of activity in 1726-1762, 1790, 1800, a brief reopening in 1815, and a financially disastrous attempt in 1824 that lost its adventurers around £75,000. Herland's most significant technical contribution came in the 1790s: a new engine house was completed at Old Herland by November 1791, with the engine steaming the following year, and by July 1792 North Herland too was pumped dry. In 1797 Herland took delivery of a Boulton & Watt rotative engine, and the mine went on to install a 64-inch cylinder single-acting Boulton & Watt pumping engine, the largest of its type ever erected in Cornwall. By 1800 the mine was producing around 2,000 tons of copper ore annually, among the most productive workings in the county over that period. Richard Trevithick himself installed a further engine at Herland in March 1815, though it initially suffered construction faults before running successfully. The mine's final working period came from around 1854 to 1874, by then combined with its neighbour as Rosewarne and Herland United.

Geology

The mine worked copper lodes of the Tregonning and Gwinear mining district, part of the granite-related hydrothermal mineralisation of west Cornwall, alongside a notable yield of native silver.

Geological setting: Hydrothermal Deposits (well documented example), Veins and Lodes (well documented example)

Workings

By 1726 the mine's workings had reached around 120 fathoms and were pumped by a 70-inch Newcomen-type engine; the 1790s saw Herland re-equipped with Boulton & Watt engines, including a 64-inch cylinder single-acting pumping engine, the largest of its type ever erected in Cornwall, and a further engine was installed by Richard Trevithick in 1815.

Closure

The mine worked intermittently over more than a century, with its final period of activity from around 1854 to 1874 as Rosewarne and Herland United, before closing for good.

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.

• By 1726 the mine's workings had reached around 120 fathoms, pumped by a 70-inch Newcomen-type engine; by 1800 the mine was producing around 2,000 tons of copper ore annually. ¹
• Herland installed a 64-inch cylinder single-acting Boulton & Watt pumping engine in the 1790s, the largest of its type ever erected in Cornwall, and Richard Trevithick installed a further engine there in March 1815. ¹

Sources

1. (secondary) Herland Mine — Graces Guide to British Industrial History
2. (primary) Rosewarne and Herland United Wheal Royal mine plans — British Geological Survey / The Coal Authority
3. (secondary) Wheal Herland (Old Herland Mine; Manor Mine; North Wheal Herland), Rosewarne and Herland United Mines — Mindat

Record created: 23 August 2026 · Last researched: 23 August 2026