Joshua Rowe and the Great Crinnis Copper Mine 1809

Some of the following text is adapted from my St Austell book, The Porcelain Parish, published in 2023. However, new information has since come to light, which I have added here, making the subject worthy of a fresh look. History is fluid, and I like to keep up the pace.

Great Crinnis, near Charlestown and St Blazey, became one of the most remarkable copper mines in the St Austell district during the early nineteenth century. The mine had previously been known as Wheal Fanny and later Old Crinnis. Although earlier workings existed on the site, its great period of success began with Joshua Rowe of Torpoint, a rope, paint and varnish manufacturer who became involved in the mine in 1809.

A map of the workings of the Great Crinnis and Appletree mines

At first, Crinnis appeared to offer little promise. Captain James Michael, an experienced Cornish miner, reportedly dismissed the abandoned workings as being “not worth a pipe of tobacco.” Rowe and his fellow adventurers nevertheless began working the mine again. Their early efforts produced disappointing results, and one by one the other investors refused to continue paying their share of the costs. Rowe was left carrying much of the financial burden himself.

His persistence was eventually rewarded. In 1811, after spending several hundred pounds opening a new section of the workings, Rowe encountered an exceptionally rich body of copper ore at a depth of only about ten fathoms, or sixty feet. The discovery transformed Crinnis almost overnight. Former adventurers returned and attempted to claim their share of the mine’s new wealth. Rowe challenged them through the courts and, despite reportedly spending around £20,000 on the dispute, eventually won his case. £20,000 equates to just over two million pounds today.

The adits of Great Crinnis Mine.

The mine then became extraordinarily profitable. Within only four or five years, it had generated a clear profit of approximately £168,000—around 21 million pounds today. One of Rowe’s principal partners was Alderman Matthew Wood, later Lord Mayor of London, who held 24 of the mine’s 64 shares. Between May 1813 and December 1814 alone, Wood received £24,098 as his share of the profits.

Contemporary records demonstrate just how rapidly production increased. Between 1811 and May 1816, Crinnis raised approximately 39,246 tons of copper ore, which sold for about £298,516. This is around 38 million pounds in today’s money. The ore yielded roughly 3,500 tons of pure copper, and one historical account calculated the mine’s profit during this period at about £120,000. At its busiest, as many as 700 people were employed at the mine.

A later account provides an even broader indication of the deposit's enormous value. It stated that between 1803 and 1828 the copper ore raised from Crinnis realised approximately £1,400,000, with profits of about £400,000 reportedly divided among the adventurers. Particularly striking is the claim that this wealth had been extracted from only a very small portion of the central lode, which was said to vary between 17 and 24 feet in width. Although these figures were themselves reported historically as estimates, they reinforce the exceptional richness and scale of the Crinnis deposit.

A share certificate for the Great Crinnis Copper Mining Company. Lyndon Allen Collection.

The surviving production figures also show the remarkable speed at which the miners followed the ore underground. In 1811, much of the copper was being obtained from less than fourteen fathoms below the surface. By 1812 the workings had reached about twenty-two fathoms, by 1813 about thirty-four fathoms, and by 1814 about thirty-eight fathoms. By 1815–16 miners were working at around fifty fathoms.

Keeping these increasingly deep workings free of water required considerable pumping power. Until midsummer 1814 the mine relied on a water engine. A 24-inch cylinder fire engine was then erected, and in May 1816 a new Woolf engine, with a large cylinder measuring about 54 inches in diameter, was put to work.

Crinnis was part of a much wider period of prosperity in Cornish copper mining. The wars with France increased demand for copper, particularly for military uses and for copper sheathing on ships. Improvements to pumping engines associated with Boulton and Watt also allowed deeper mines to be worked more economically. By 1810, Crinnis was listed among Cornwall’s most productive copper mines.

There was also an earlier connection between copper and the St Austell district. An historical account records that copper smelting had been attempted at Polrudden, St Austell, around seventy years before 1778 by Mr Scobell, joined by Sir Talbot Clark and Mr Vincent. It was claimed that the first piece of copper produced in this way in the country was smelted, refined and brought to perfection there. However, smelting in Cornwall was ultimately disadvantaged by the shortage of suitable local fuel and the expense of importing coal from South Wales. By about 1810 only one Cornish smelting house remained in operation, at Hayle, and much Cornish copper ore was consequently shipped to South Wales for smelting.

The success of Crinnis also appears to have influenced Joseph Austen, later known as Joseph Treffry, one of Cornwall’s most important nineteenth-century industrialists. Austen had connections with Joshua Rowe and became increasingly interested in mining ventures. In November 1814, correspondence records Austen dealing with costs connected with Wheal Willington, while nearer St Austell he also had interests in Cuddra Mine.

By February 1815 Austen held a 1/32 share in the Cuddra Adventurers. His involvement proved timely. In April 1817 he received news that the Crinnis Great Lode had been cut at Cuddra, with copper present on one side and black copper on the other. Contemporary estimates suggested that, if the vein continued at the same quality, a single share might be worth around £2,000. This was compared with a similar share in Crinnis which had reportedly produced about £1,900 profit in only twenty months.

Austen’s journeys between Cuddra and Charlestown also brought him into contact with numerous smaller mines in the surrounding countryside, including Wheal Treasure, Wheal Fortune, Wheal Chance and Lanescot. By the summer of 1817, reports suggested that Cuddra was prospering, with wagons regularly carrying copper ore to Fowey. Captain Barrett inspected the mine and described its main lode as being of particularly high quality. These developments illustrate how the spectacular success of Crinnis encouraged further investment and exploration throughout the St Austell mining district.

Crinnis itself continued to develop. Its workings eventually extended for approximately two miles beneath the sea and three miles inland. The success naturally attracted competition. Only months after the rich discovery, another mine opened nearby in the Crinnis Woods. These workings became known as Wheal Regent, named after the Prince Regent, later King George IV.

Appletree and its engine house and adit below. Copyright Lyndon Allen Collection

Despite its extraordinary early success, Great Crinnis eventually declined. Other copper mines followed, including South Crinnis, also known as Appletree Mine, which opened many years later. Between 1849 and 1856, Appletree sold 6,097 tons of copper ore, valued at £44,950, and between 1857 and 1866 another 10,478 tons were sold for £59,534. Conditions underground were extremely difficult. The mine was poorly ventilated, temperatures reportedly reached 90–100°F, and miners sometimes worked stripped to the waist. Lung disease and tuberculosis were serious problems among the workforce. Appletree finally closed in 1866.

The wealth generated by the district’s mines also encouraged the development of copper smelting at Charlestown. In 1834, John Taylor and Company established a smelting works at Mill Lane, behind the Grove. It initially processed tin ore from Great Polgooth and later reopened under new management. The works eventually came under a consortium of major Cornish tin smelters. However, the copper and tin boom of the early 1870s was short-lived. The industry collapsed dramatically in 1873, and the Charlestown smelting works finally closed in 1884.

By then the economic character of Charlestown and St Austell was changing. The movement of china clay through Charlestown harbour was increasing rapidly, eventually accounting for two out of every three vessels using the port. Copper, tin, lead and zinc declined in importance, and the district entered a new industrial period dominated by china clay.

Fanny's Shaft, cordoned off with wire netting.

Great Crinnis therefore represents an important turning point in the industrial history of the St Austell area. Its extraordinary discovery in 1811 transformed an apparently worthless, abandoned mine into one of Cornwall’s richest copper ventures. The wealth it produced encouraged further mining investment, influenced figures such as Joseph Austen, created employment for hundreds of people and contributed to the development of the wider Charlestown industrial landscape. Its later revival under the company formed in 1852 also demonstrates the enduring attraction of the great Crinnis lode decades after Joshua Rowe’s remarkable success. Its rise and eventual decline reflect the broader history of Cornish mining: spectacular discoveries, investment and technological innovation followed eventually by falling production and the emergence of new industries.

I consider this to be an accurate account of the history of the Great Crinnis mine, later renamed Carlyon Consolidated.

Written by Lyndon Allen in 2026.