The explosion in growth of the Cornwall and west Devon mining industries created a demand for a number of supporting industries to supply both the mines and its workforce, as well as processing its output.
By 1840 Cornish engines and engineers were the most distinguished in the world.
Included within these industries (many new in Cornwall) were: foundries; copper, tin and silver-lead smelters; rope-walks; ochre-works; arsenic works; chemical works; charcoal manufactories; candle factories; crucible works; brickworks; clothing factories; scientific instrument manufactories; gunpowder mills and explosives factories.
Parts for steam engines were made in foundries and forges. Initially Cornwall did not possess any foundries capable of casting and boring cylinders. The Darby firm of Coalbrookdale in Shropshire (established 1709) was one of the principal founders of iron cylinders and, together with others in the Midlands, supplied almost all the early engines in Cornwall.
It was not until the end of the 18th century that Cornwall began making its own steam engines. The expiry of the Watt Patent in 1800 heralded a period of experimentation in Cornwall by engineers such as Sims, Woolf, Trevithick and Hornblower. From about 1820 virtually all the local mines bought ‘Cornish’ and by 1840 Cornish engines and engineers were the most distinguished in the world. Globally, as new mineral discoveries were made, so mine engines were despatched to South America, Australia, Ireland and South Africa; in fact wherever deep mining was being progressed.
Three of the largest foundries were Harvey’s Foundry (Hayle), Copperhouse Foundry (Hayle) and Perran Foundry (Perranarworthal). Together they were responsible for the employment of more than 3,000 people during the 19th century.
Harvey’s Foundry, Hayle (1779-1903)
Harvey’s was indisputably the greatest of the Cornish foundries. It was established in 1779 by John Harvey and greatly expanded by his son Henry in collaboration with the renowned engineer Arthur Woolf. It became the foremost engine foundry in the world with an international market served through the company’s own port at Foundry town, Hayle.
Perran Foundry, Perran-ar-Worthal (1791-1879)
The Perran Foundry and Wharf stand on the level valley floor at the navigable limit of an inlet leading to the River Fal. It was the second largest foundry in Cornwall and is considered one of the most important surviving industrial monuments of its period in southern Britain.
Perran Foundry was established by the Fox family in 1791, trading under the name Foxes & Perran Foundry Co, and between 1858 and 1879 under the name Williams & Perran Foundry Co after the Williams family became major shareholders. It manufactured a wide range of mining implements and steam engines. During this period a complex of leats, foundry buildings, stores, facilities for transport and other services including offices and worker's houses were developed. By 1860, the works covered six acres and employed 400 men. It continued in operation until a decline in the fortunes of the local mining industry forced it to close in 1879.
Copperhouse Foundry (1820-1869)
The Cornish Copper Company started a foundry in their former copper smelting complex in Hayle when smelting ceased there after 1819. This traded as Sandys, Carne and Vivian and was one of the three great Cornish engine foundries. The 80-inch Robinson’s Shaft engine at South Crofty Mine, Pool (built in 1854), is testament to the quality of the products being produced by the foundry at the time.
Cornwall and west Devon foundries and engineering works also specialised in the manufacture and supply of a wide range of mining equipment. There were important foundries in Tavistock (eg. Mount Foundry), Charlestown, St Just, Tuckingmill, Redruth, St Blazey and other mining districts.
Holmans of Camborne was established as a boiler works at Pool in 1801. It developed into the principal employer in the district (over 3,000 employees) and expansion had a significant impact upon the urban development of Camborne. In the early 20th century Holmans became synonymous worldwide with excellence in rock-drills and air compressors.
Tin smelting in Cornwall was, on the whole, a more capital-intensive and lucrative business than mining and was controlled by a ‘ring’ or cartel of a few families. Money was often advanced to mines or miners, to be re-paid in tin. For the Bolitho family of Penzance this practice led to them becoming bankers. Thomas and William Bolitho founded The Mounts Bay Commercial Bank in 1807 in the count-house of their Chyandour Smelting House. The Consolidated Bank of Cornwall was taken over by Barclays Bank in 1905. The principal Cornish families engaged in tin smelting were the Daubuzes, the Williams, the Harveys and the Bolithos.
A landmark technical improvement in Cornish tin smelting came in 1702. This was the introduction of the reverberatory furnace at Newham (Truro). This used coal instead of charcoal and the charge of tin was no longer mixed with (and contaminated by) the fuel but was reduced by the application of heat alone.
By the 19th century, most tin smelting was conducted in reverberatory furnaces, although the larger and more important blowing houses remained until the mid century, producing the purer and more valuable ‘grain’ tin. Tin smelters within the region were initially concentrated close to the Stannary Towns and navigable rivers or harbours, and near the principal tin mines. As the century progressed, smelting houses were established in new or developing mining areas as these, in turn, became important for tin production. Most of the major early tin smelters were concentrated in Penzance, Hayle, Truro and the St Austell area. Later, when rail transport had developed (and after tin ‘coinage’ (tax) had been abolished) Redruth became an important centre for tin smelting.
The technical complexity of copper smelting meant that sites needed to be close to a plentiful and consistent mix of copper ores. Large amounts of coal were also needed for fuel and the reduction process. Copper smelting was carried out in Cornwall in several locations but principally by the Cornish Copper Company at Hayle (1758-1819). In time, however, this was proven to be uneconomic and all copper was subsequently smelted in south Wales after 1819, it making better commercial sense to ship the ore to the coalfields.
Shipments were mostly of hand-picked, crushed (‘cobbed’) raw ore but later partly smelted regulus was sent also. While ores were initially sent to Bristol for smelting, Swansea was later to dominate due to its readily accessible coal reserves and good shipping links. The transport of millions of tons of copper ore accounts for the once extensive mule trade, the tramroads and railways, quays, industrial harbours and shipping fleets. The ‘Welsh Fleet’ brought coal for Cornwall’s steam engines as back loads in the copper-ore schooners. In the Swansea region, copper smelting (and indeed much of the tin-plate industry) was in the hands of Cornish industrialists, including the Williams and Vivian families.
During the early 19th century Cornwall pioneered world arsenic production as a by-product of tin and copper mining in the western part of the Site. The first commercial British arsenic was produced at Perran-ar-Worthal in 1812, followed by a works at Bissoe (1834) in the Carnon Valley that became a stronghold of arsenic production mainly trading with the expanding Lancashire cotton industry which used it in pigments and dyes.
During the latter half of the 19th century the working of arsenic provided several more years of profitable work for some flagging copper mines, and in some cases these ores became their principal output. Substantial works were established at the English Arsenic Company factory at Roseworthy, Gwithian and at Greenhill near Gunnislake, but the largest in the region was at Devon Great Consols, which at its peak produced 3,000 tons of refined arsenic a year. In the 1870s a handful of mines in the Tamar Valley mining district were producing over half of the world’s arsenic.
In 1836 alone, 30 tonnes of gunpowder were used in Cornish mines.
Gunpowder was very expensive, largely because of the monopoly on saltpetre. It was made by mixing and grinding charcoal, sulphur and saltpetre together in water powered incorporating mills. The process was complex with many stages, and also extremely dangerous as gunpowder dust could be readily ignited by the smallest spark.
Gunpowder was imported into Cornwall until 1808 when the first Cornish gunpowder factory opened at Cosawes Wood, Perran-ar-Worthal, about 5 miles from Falmouth. The site at Cosawes and at other works - such as the one at nearby Kennall Vale which followed in 1813 - were chosen for their seclusion in wooded river valleys. This ensured both the availability of water power and the relative safety of nearby settlements, shielded as they were by the trees. These also served to shield the process buildings and storage magazines from one another, should an explosion take place. The roofs of the buildings were also designed to blow off relatively harmlessly in the event of a detonation.
The adoption of gunpowder for mine blasting in Cornwall in1689 represented a great technological breakthrough. By 1836 the consumption of this was considerable with 30 tonnes being used in Cornish mines. The first practical high-explosive ever fired in a mine in Cornwall was that at the Restormel Iron Mine (managed by John Taylor) at Lostwithiel in 1846. By the 1870s high explosives were starting to come into wider use being more efficient than the relatively slow burning gunpowder.
In 1866, Alfred Nobel (1833-96) invented dynamite. This nitroglycerine-based explosive reached Britain the following year and Cornwall soon after. The principal Cornish gunpowder manufacturer, Shilson, set up the National Explosives Company in 1888.
The first factory was built amidst the protective sand dunes of Hayle Towans and soon became one of the leading manufactories in Britain. In 1889 the British & Colonial Explosives Company was formed and the site chosen for the new factory was a hectare of remote old mining ground at St George’s Common on the cliffs west of Perranporth. Extensive structures survive, both at Hayle and at Perranporth.