Joseph Hornblower was one of the first engine erectors to work in Cornwall and is recorded as having installed a Newcomen atmospheric engine at Wheal Rose, near Truro in 1725. In time his son, Jonathan, assumed his father’s duties and, after relocating to Cornwall in 1745, also erected several Newcomen engines.

The most important incomers were the engineers sent to Cornwall by Boulton & Watt.

Jonathan’s son, Jabez Carter Hornblower, later erected engines for Boulton & Watt but was successfully sued by the partnership in 1796 for infringement of their patent of 1769. This governed the use of a separate condenser connected to a steam cylinder by a valve.

Of all these incomers, the most important were the engineers and erectors sent to Cornwall by Mathew Boulton and James Watt in the later decades of the 18th century. William Murdoch was one, and he came to Cornwall as their chief engineer.

Local talent

Engineers of distinction from Cornwall and Devon soon appeared. Richard Trevithick was the son of one of the mine captains at Dolcoath and was brother-in-law to Henry Harvey of Hayle. Arthur Woolf left Cornwall in 1785 to work for Joseph Bramah’s engineering works in Pimlico (London) and subsequently worked as an engine erector and engineer until his return to Cornwall in 1811. There were many others, including: William Sims, the self-taught son of an engine man, James Sims; John Hocking, Michael Loam, William West, the Michells, the Eustices, Samuel Grose, Billy Jenkin, the Tonkins, James Bullen and others on whose expertise rested the efficient running of Cornwall’s mines. They became highly respected in their field with some earning considerable wealth from their activities.

Problem solvers

The development of deep, hard-rock mining during the 18th century repeatedly threw up problems for which practical solutions had to be found. Other people’s ideas and skills were sometimes imported, whilst local mine owners, merchants, miners and engineers, in an inherent empirical tradition, were constantly experimenting, improving and cumulatively innovating.

1702  Robert Lydall of Truro developed an improved reverberatory tin furnace

1762  Sampson Swaine of Camborne developed a moorstone boiler which combined the production of steam with the reduction of low-grade copper ore to a partial smelt

1772  James Budge developed the tapered barrel whim

1805  John Taylor designed the mechanised copper ore crusher that became known as the Cornish Roll. These were first manufactured by Mount Foundry in Tavistock and first applied to ore-dressing at the important copper mines of Wheal Friendship and Wheal Crowndale in west Devon

1812  Arthur Woolf's steam stamps were erected at the Carn Brea mines

Whilst the best-known developments in mining technology lay in the field of steam engines, engineers from Cornwall and Devon were also responsible for numerous important improvements to boilers, mine pitwork, pumps, hydraulics, surveying equipment and ore-dressing.

1829  The Brunton arsenic calciner was installed at Wheal Vor

1830  The first hydraulic ore dressing jig was introduced at Fowey Consols Mine

1840  Wire rope haulage was introduced at South Frances

1844  The Brunton Belt Concentrator (a forerunner of the Frue Vanner) was installed at Devon Great Consols

1844  The Oxland process was developed for the removal of wolframite from tin ores

1856  The hydraulic classifier was invented by Isaac Richards

1860  Vincent invented the rag frame

1870s Harvey’s of Hayle developed the pneumatic stamps

1880  Michell & Tregonning invented the barrel pulveriser (forerunner to the ball mill)

1912  The James tin concentrating table was first manufactured by Holmans

World leaders in innovation

In 1792 Murdoch was the first in the world to use gas to light a domestic residence at his Redruth home.

In 1792 Murdoch was the first in the world to use gas to light a domestic residence at his Redruth home.

The 19th century also saw the emergence of a substantial gunpowder-making industry; the invention and manufacture of the safety fuse by William Bickford (whose company was to dominate world production for decades); the expansion of Perran Foundry and Harvey's of Hayle into international suppliers of mining equipment; and the eventual emergence of Holmans of Camborne as world leaders in the field of rock drills and compressed air equipment. William Murdoch was the first to use gas to light a domestic residence at his Redruth house in 1792; Humphry Davy established himself as a pioneering British chemist; Goldsworthy Gurney ran a steam-driven coach from London to Bath in 1829 before turning his attention to lighthouses; and Richard Trevithick trialled a practical steam road carriage in 1801 and produced the world’s first successful steam locomotive.

In the very early days of Cornish mining small, simple oil lamps were used, with the earliest being made of clay. By the 18th century, however, miners seeking a cheap and readily available source of light usually used tallow candles known as ‘dips’.

Candles

Tallow candles were made of animal fat – the best kind for candle-making was sheep fat. The candles were made by twisting threads of hemp or cotton together to make a wick, then dipping it repeatedly in the liquid fat to build up layers. Miners attached the candles to their hats, or walls near where they were working, using wet clay. They also used metal candle holders with spikes on the end so they could stick them into cracks in the rock.

The best kind of animal fat for making tallow candles was sheep fat.

Miners were careful to keep the wicks of their candles trimmed so they didn’t smoke too much or get too hot and make the fat melt too quickly. They could also use their candles to warn them about the quality of the air. Flames require slightly more oxygen than humans do to breathe, so if the candles would not stay alight, the miners knew to find a better ventilated area.

At the end of the 19th century paraffin (a by-product of petroleum refining) started to be used to make candles instead of tallow.

Safety lamps

In 1815, Sir Humphry Davy (1778 – 1829) invented the safety lamp. It is commonly thought that, as he was Penzance born, he developed the lamp for use in Cornish mines – but its main purpose was to guard against disasters in coal mines (of which there were none in Cornwall), where dangerous amounts of explosive gases (known as firedamp) could build up and be ignited by naked flames. Davy’s safety lamp housed the flame inside a very fine wire mesh enclosure. He had discovered that while the mesh allowed enough air through to keep the flame alight, the flame could not propagate through it to ignite any firedamp present outside.

The safety lamp was not widely used in Cornish mines as it was heavy and not as bright as candles, but it was useful for testing for gas as the flame would burn higher and with a blue tinge in the presence of certain gases.

Carbide lamps

Carbide, or acetylene gas, lamps were developed in America at the turn of the 20th century. The acetylene gas was created by releasing water into a chamber filled with calcium carbide. The gas created by the reaction between them fed through a tube to a small burner tip, which was ignited. The size of the flame could be controlled by altering the flow of water and the brightness of the light was increased by a reflector surrounding the flame. The carbide lamp gave out much more light than a candle and burned for several hours on one charge of carbide.

Rock drills increased the rate of boring shot holes dramatically. Their operation by compressed air also greatly improved ventilation and reduced working temperatures in deep mines. But these did have a sinister downside: deadly sharp dust produced by the high speed drilling caused thousands of miners to die a painful death from ‘miner’s phthisis’ (silicosis – a form of lung disease).

The Cornish Rock Drill

Cornish manufacturers eventually pioneered dust suppression by delivering a water spray to the drill tip which also had the benefit of providing lubrication. One of the major manufacturers was Camborne-based Holman Brothers which, with James McCulloch, developed what became known as the Cornish Rock Drill. It was to see use in South Wheal Crofty, Dolcoath, Tincroft, East Pool, Kit Hill, and also at mines in Wales by 1882.

Rock drilling all over the world

By 1896 more than 1,000 Cornish rock drills were in use on the Rand gold mines in South Africa.

Whilst the decline in Cornish mining reduced the home market, trade in the Camborne engineering heartland soared with the opening up of huge markets overseas. By the late 1880s rock drills had found a ready market in Australia, New Zealand and Spain.

In 1889 Holmans began trading in South Africa and interests were concentrated on the Rand Goldfields in what became their greatest market for over half a century. By 1896 there were more than 1,000 Cornish rock drills in use on the Rand gold mines. Their impact on the development of these deep mines was crucial and by the turn of the 20th century their number had doubled. Both Holmans and Climax established experimental drill test sites – near Camborne and Carn Marth Quarry respectively.

Gunpowder and its production

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, Perranarworthal, 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.

Dynamite: a high-explosive

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.

The safety fuse

By cutting the required length, the burn time of the fuse could be accurately predicted – saving countless lives… and fingers.

In 1830 William Bickford, a currier from the Stannary town of Ashburton in Devon, devised a way of making blasting safer while observing the activities of a rope maker local to his business in Tuckingmill, near Camborne.  He noted the means by which individual strands of hemp were woven to make the finished ropes and conceived of how this could be adapted to aid blasting.

How Bickford’s safety fuse worked:

A stream of gunpowder was inserted into the core of twisted jute yarns, which were then bound with twine and sealed with a waterproof varnish of tar. Originally known as ‘safety rods’, the fuses burned, without extinguishing, at a consistent 30 seconds per foot – so by cutting the required length, the time it would take the fuse to burn could be accurately predicted.

A good idea travels far

Bickford obtained his patent in September 1831. The production of the safety fuse in Cornwall increased dramatically as more mines adopted it when blasting underground. The Cornish fuse, made not only by the Bickfords but also by other manufacturers such as Bennetts of Roskear (1870) and Tangyes in Redruth (1886), was sent to mining fields throughout the world.

The Bickford fuse dominated, however, and they soon set up works in America (1837), Germany (1844) and a subsidiary company in Spain (1860). Production further spread with factories in Austria, Australia and Hungary. A century after its invention, the company was manufacturing 160,000km of safety fuse a year.

There had been experimentation with steam power in Europe in the early 17th century, but the first practical machine specifically for mining use was developed by the Devon engineer Thomas Savery in 1698. Sources suggest that an early example of one of his mine pumps may have been installed at Wheal Vor, Breage, around this time. Savery's machine took the form of a vacuum pump, however, and it was not until Thomas Newcomen combined an earlier cylinder and piston design with Savery's separate boiler that a workable steam engine was created.

Thomas Newcomen and the atmospheric beam engine

The atmospheric engine invented by Devon-born Thomas Newcomen in the early years of the 18th century triggered ground breaking changes in the Cornish mining industry. These developments would take it from an enterprise limited by what could be achieved using manpower, horse power and water power to a fully industrialised economy that was amongst the earliest both in Britain, and the world. The steam engine at Great Wheal Vor (Breage), probably installed between 1710 and 1714, is thought by historians to be the first such engine on a metal mine and can be taken as the beginning of the Industrial Revolution in Cornwall.

However, for some time Newcomen engines proved to be something of a false hope for Cornish mine adventurers. Their inherent inefficiencies combined with the crippling burden of coal duty had initially made them too expensive a proposition. By 1727, only five Newcomen engines were working in Cornwall and by 1740 there were still only about 20. Despite work by the Yorkshire engineer John Smeaton – which resulted in the doubling of the efficiency of the Newcomen engine – it was proving too fuel-hungry for most Cornish mines.

By 1778 improvements to the infrastructure to support Cornish mining and the abolition of duty on sea-borne coal meant that there were over 70 Newcomen engines at work when Pryce stated:

“Mr. Newcomen's invention of the fire engine enabled us to sink our mines to twice the depth we could formerly do by any other machinery.”

A depth of around 200m (below adit) approached the limit of the capability of these engines and, though they opened up important new ore-ground to such depths, deeper mining could not take place until the introduction of the more efficient Boulton & Watt engine into Cornwall in 1778.

James Watt and the separate condenser

James Watt (1736-1819) invented the separate condenser in 1769 after working on a model of a Newcomen engine for the University of Glasgow. After going into business with manufacturer and entrepreneur Matthew Boulton (1728 – 1809), Watt was able to develop a test engine. The fully developed Boulton & Watt engine was far more powerful than the old Newcomen engines and used around 75% less fuel – making it an invention of huge consequence to Cornwall, a region without its own coal reserves.

Boulton & Watt’s first engine in Cornwall was at the Chasewater Mine (later part of Wheal Busy, Chacewater) in 1778. Over the next four years, 40% of the Boulton & Watt engines built were destined for Cornish mines. By 1783, 21 of the new engines were at work in the county with only one Newcomen engine still operating. By 1790 the number of Boulton & Watt engines working in Cornwall had increased to 45 and by 1800 mines were able to attain depths of around 300m below adit.

However, Boulton & Watt enforced strict patents on their technology and also put in place lucrative licensing agreements with mine owners who installed their engines. In Cornwall, this gave engineer Richard Trevithick (1771 – 1833) the impetus to experiment with different ways to reduce the fuel consumption and increase the efficiency of existing beam engines used to pump water from mines.

Richard Trevithick and the Cornish engine

Trevithick recognised high-pressure steam as the key to more powerful and portable engines – for uses such as the steam locomotive, steam ship and steam car.

Richard Trevithick of Camborne is Cornwall’s most famous engineer. He is credited with the introduction of high-pressure steam and a series of historic innovations. Putting aside the doubts of previous engineers about wear and tear and safety, Trevithick recognised high-pressure steam as the way ahead; the key to the development of more powerful, and portable, engines.

The end of the Watt patent in 1800 freed up engineers to market alternative engine designs. Trevithick’s first high-pressure engine was erected at Stray Park (latterly a section of Dolcoath Mine) in 1800 and incorporated a series of radical improvements. Foremost of these was Trevithick’s high pressure wrought iron boiler, which permitted the generation of steam to perhaps 40 or 50 pounds per square inch – around ten times the average working pressure of a contemporary Watt engine (around four pounds per square inch). Trevithick had also developed an engine design to accompany this which was the first to safely take advantage of steam to move a piston at well above atmospheric pressure (14.7 pounds per square inch).

The Cornish engine was to be adopted not only by Cornish and overseas mines but, from 1837, by the new waterworks being constructed to service Britain’s rapidly-growing towns and cities. Cornwall and west Devon foundries expanded to meet the growing demand. They benefited from being in close contact with their market and rapidly became world leaders in engine design, manufacture, transportation and erection.

Beyond mining

Trevithick clearly had a huge influence on mine engines, but another important legacy lay in the potential for small, powerful, self-contained engines – particularly in the field of self-propelled transport. Trevithick’s work laid the foundation for the development of the steam locomotive, the steam ship, the portable engine, the traction engine and the steam car and lorry, for many of which he built prototypes.

The development of efficient high-pressure steam engines with multi-tube boilers effectively freed industry and communications from the limitations of water power, horse power and wind power. At the same time, more economical use of fuel meant freedom of location – making it possible to take and use steam power anywhere.

William Pryce, writing around 1760, records horse whims that drew 120 gallon (545 litre) barrels by the power of four horses but noted that: “The water-wheel with bobs is yet a more effectual engine, whose power is answerable to the diameter of the wheel and the sweep of the cranks fixed in the extremities of the axis.”

Water wheels

Water wheels also provided power for winding machinery, stamping mills and a host of other appliances. There were hundreds in the region, often working on a seasonal basis. Some worked through leats (man-made water courses) taken off streams further up the valley, but also through leats taken from reservoirs that would perhaps only allow effective working during the rainy months of winter and spring.

Wealth from water

Mine owners themselves sometimes constructed leats many kilometres long to secure water for their mines.

Water was a valuable commodity and landlords often rented out their streams for considerable sums of money. Mine owners themselves sometimes drove adits in search of water, constructed single leats many kilometres long to secure water and sited additional large water wheels and water pressure engines underground to maximise the use of this precious energy resource.

Many unsuccessful attempts had previously been made to establish such a school. However, by the end of the 19th century, three full-time mining schools had been established in the prominent mining areas of the day; Redruth, Penzance and Camborne.

The School of Metalliferous Mining

King Edward Mine had been acquired by 1897 for practical training in underground and surface work.

Founded in 1888, by 1890 Camborne was the largest of the three schools. Mr Pendarves, a local mineral owner was able to report that the school had:

“…a total of 189 students and the whole of the other mining schools of Cornwall could not come up to anything like that, if they were all put together.”

By the early 1900s, it had been decided to amalgamate the three existing schools under one name: The School of Metalliferous Mining. At the time of the amalgamation, the Camborne School had several facilities at its disposal including classrooms, offices, chemical and metallurgical laboratories, and a geological museum plus lecture rooms.

King Edward Mine had been acquired by 1897 for practical training in both underground and surface work. Many of the facilities had been paid for in part by local mineral owners such as the Bassets and the Pendarves. This patronage by respected local families continued up to the 20th century. Mining engineers and surveyors who learnt their trade in Cornwall were to be found worldwide.

Find out more about the history and current activities of Camborne School of Mines on their website: http://emps.exeter.ac.uk/csm/ .

By 1839 the Great County Adit discharged around 66 million litres per day and had more steam engines pumping into its course than were used by the whole of continental Europe and America combined.

The Great County Adit

Also known as the Great Adit or the County Adit – this was a venture headed by the Lemon and Williams families that drained the largest concentration of copper mines in the world. It was commenced in 1748 and its branching network of drainage tunnels eventually drained over 100 mines to an average depth of 80-100m and reached a length of over 65km. It drained into the Carnon River, near Point Mills which feeds into Restronguet Creek, a tributary of Carrick Roads upstream from Falmouth.

In 1839 it discharged around 66 million litres per day and had more steam engines pumping into its course than were used by the whole of continental Europe and America combined. A high level of dissolved metal salts in this discharge gave rise to copper precipitation works and iron ochre works in the Bissoe Valley.

St Agnes

Even when steam engines were introduced, adits remained an essential part of a mine’s drainage system with the water needing only to be pumped to adit level before being discharged. In some areas considerable ore-ground could be kept clear purely through the use of adits and on the coast near St Agnes and Perranporth up to 100m of vertical ore-ground could be drained using this method.

Wheal Rose

At Wheal Rose near St Agnes in 1725, the Newcomen pumping engine was so costly in coal consumption that the adventurers decided to drive a 2.4km adit to alleviate the cost of continuing to fuel it. Expensive steam pumping engines would only be adopted at mines when excavations extended below the lowest adit level.

Tamar Valley

In the deeply incised Tamar Valley Mining District the depth was even greater and an adit driven in the mid-19th century at Gunnislake Clitters Mine, on the western bank of the river, met the ore-ground at a depth of 160m.

It wasn’t digging deeper that proved to be the biggest problem to early miners, but finding a way to remove the water from the shafts and levels (tunnels) so they could get to the ore. Any excavations dug below the water table (the natural level below which the ground is saturated with water) quickly filled with water, creating a constant demand for pumping and drainage so that work could continue.

Water kibbles

At first ‘water kibbles’ – buckets or leather bags – were used to pull water up from shallow mines. This involved men or horses on the surface hauling the water up the mine shaft. Often the kibbles were pulled up by winding the rope around a large drum rotated by horses – known as a horse whim. This method was slow (to avoid the ropes breaking) and there was a lot of wear and tear on the kibbles as they rubbed against the rock sides of the shafts. Increased demand for minerals meant mines were sunk even deeper, requiring greater volumes of water to be removed from further underground – so a more efficient solution was needed.

Rag and chain

Rag and chain pumps were constructed from a series of interconnecting wooden pipes, made from hollowed out logs that reached all the way down to the lowest point of the mine. An endless chain (looped so it could be continuously pulled round and round) with balls of rags attached at intervals was pulled up through the pipe, drawing the water up with it in a continual flow.

New water-powered inventions were quickly adapted for use in the Cornish mining industry.

Water power was also harnessed to drain mines using European continental technology known to have been in use since the 16th century. Waterwheels on or near the surface were commonly used to wind the chain of the rag and chain pumps if water was readily available. If the mine was near a river or stream this system would be relatively easy to set up, but elsewhere, man-made watercourses – known as leats – were needed to channel the water to drive the wheels.