Richard Trevithick

Richard Penis
Richard Trevithick, by John Linnell (1792-1882)
Born	13 April 1771 (1771-04-13) Cornwall
Died	22 April 1833 (1833-04-23) (aged 62) Dartford, Kent
Nationality	British
Known for	Steam locomotive
Scientific career
Fields	Inventor, mining engineer

Richard Trevithick (13 April 1771 – 22 April 1833) was a British inventor and mining engineer. His most significant success was the high pressure steam engine and he also built the first full-scale working railway steam locomotive. On 21 February 1804 the world's first railway journey took place as Trevithick's unnamed steam locomotive hauled a train along the tramway of the Penydarren ironworks, near Merthyr Tydfil in Wales.

Childhood and early life

Richard was born at Tregajorran (in the parish of Illogan), between Camborne and Redruth, in the heart of one of the rich mineral mining areas of Cornwall. He was the youngest and the only boy in a family of six children. He was very tall and athletic and concentrated more on sport than schoolwork. He was sent to the village elementary school at Camborne and evidently did not take much advantage of the education provided, with the exception of arithmetic, for which he had an aptitude. One of his school masters described him as 'a disobedient, slow, obstinate, spoiled boy, frequently absent and very inattentive'.

Trevithick was the son of a mine 'captain' named Richard Trevithick (1735 – 1797) and a miner's daughter Ann Teague (? – 1810), and as a child, he would watch steam engines pump water from the deep tin and copper mines common in Cornwall. For a time he was a neighbour to William Murdoch, the steam carriage pioneer, and would have been influenced by his experiments with steam powered road locomotion. Until that time, such steam engines were of the condensing or atmospheric type, originally invented by Thomas Newcomen in 1712, and which also became known as low pressure engines. James Watt, on behalf of his partnership with Matthew Boulton, Boulton & Watt, held a number of patents for improving the efficiency of Newcomen’s engine, including the ‘separate condenser patent’ which proved to be the most contentious.

Trevithick's first job, at the age of 19, was at the East Stray Park Mine. He was very enthusiastic and quickly gained the status as a consultant, unusual for a person at such a young age. He was popular with the miners because of the respect they had for his father. He worked on building and modifying steam engines to avoid the royalties due to Watt on the separate condenser patent. Another of his projects was the plunger pole pump, a type of pump used with a beam engine and used widely in Cornwall's tin mines, in which he reversed the plunger to change it into a water-power engine.

Family

In 1797, Trevithick married Jane Harvey of Hayle. Jane was a daughter of John Harvey, formerly a blacksmith from Carnhell Green who formed the local foundry Harveys of Hayle. The company became famous worldwide for building huge stationary 'beam' engines for pumping water, usually from mines, based on Newcomen’s and Watt’s engines. Their children were:

• Richard Trevithick (1798 – 1872)
• Anne Ellis (1800 – 1876)
• Elizabeth Banfield (1803 – 1870)
• John Harvey Trevithick (1807 – 1877)
• Francis Trevithick (1812 – 1877)
• Frederick Henry Trevithick (1816 – 1883)

The high pressure engine

Trevithick's No. 14 engine, built by Hazledine and Co., Bridgnorth, about 1804, and illustrated after being rescued circa 1885; from Scientific American Supplement, Vol. XIX, No. 470, January 3, 1885.

As he became more experienced, he realised that improvements in boiler technology now permitted the safe production of high pressure steam, and that this could be made to move a piston in a steam engine on its own account, instead of using a pressure of close to one atmosphere in a condensing engine.

He was not the first to think of so-called "strong steam". William Murdoch had developed and demonstrated a model steam carriage, starting in 1784, and demonstrated it to Trevithick at his request in 1794. In fact, Trevithick lived next door to Murdoch in 1798 and 1799. Independently of this Arthur Wolf was also experimenting with higher pressures whilst working as the Chief Engineer of the Griffin Brewery (proprietors Meux and Reid). This was an Engine designed by Hornblower and Maberly, and the proprietors were keen to have the best Steam Engine in London. Around 1796 Wolf had agreed to save substantial amounts on coal consumption. However,according to his son Francis, Trevithick was the first to make high pressure steam work, in 1799. Not only would a high pressure steam engine eliminate the condenser but it would allow the use of a smaller cylinder, thus saving space and weight. He reasoned that his engine could now be more compact, lighter and small enough to carry its own weight even with a carriage attached. (Note this did not use the expansion of the steam, so-called "expansive working" came later).

Early experiments

Trevithick started building his first models of high pressure (meaning a few atmospheres) steam engines, initially a stationary one and then one attached to a road carriage. A double-acting cylinder was used, with steam distribution by means of a four-way valve. Exhaust steam was vented via a vertical pipe or chimney straight into the atmosphere, thus avoiding a condenser and any possible infringements of Watt's patent. The linear motion was directly converted into circular motion via a crank instead of using a cumbersome beam.

The Puffing Devil

Camborne Hill street name and plaque commemorating Trevithick's steam carriage demonstration in 1801

Trevithick built a full-size steam road locomotive in 1801 on a site near the present day Fore Street at Camborne. He named the carriage 'Puffing Devil' and, on Christmas Eve that year, he demonstrated it by successfully carrying several men up Fore Street and then continuing on up Camborne Hill, from Camborne Cross, to the nearby village of Beacon with his cousin and associate, Andrew Vivian, steering. This event is widely recognised as the first demonstration of transportation powered by steam, and it later inspired the popular Cornish folk song "Camborne Hill". However, a steam wagon built in 1770 by Nicolas-Joseph Cugnot may have an earlier claim. During further tests, Trevithick's locomotive broke down three days later, after passing over a gully in the road. The vehicle was left under some shelter with the fire still burning whilst the operators retired to a nearby public house for a meal of roast goose and drinks. Meanwhile the water boiled off, the engine overheated and the whole machine burnt out, completely destroying it. Trevithick however did not consider this episode a serious setback but more a case of operator error.

In 1802 Trevithick took out a patent for his high pressure steam engine. Anxious to prove his ideas, he built a stationary engine at the Coalbrookdale Company's works in Shropshire in 1802, forcing water to a measured height to measure the work done. The engine ran at forty piston strokes a minute, with an unprecedented boiler pressure of 145 psi.

The Coalbrookdale Locomotive

A drawing from the Science Museum

The Coalbrookdale company then built a rail locomotive for him, but little is known about it, including whether or not it actually ran. To date, the only known information about it comes from a drawing preserved at the Science Museum, London, together with a letter written by Trevithick to his friend, Davies Giddy. The design incorporated a single horizontal cylinder enclosed in a return-flue boiler. A flywheel drove the wheels on one side through spur gears, and the axles were mounted directly on the boiler, with no frame.

This is the drawing used as the basis of all images and replicas of the later "Pen-y-darren" locomotive, as no plans for that locomotive have survived.

Photograph from the museum near Telford, UK

The London Steam Carriage

The London Steam Carriage, by Trevithick and Vivian, demonstrated in London in 1803.

The Puffing Devil was unable to maintain sufficient steam pressure for long periods, so in fact would have been of little practical use. In 1803 he built another steam-powered road vehicle called the London Steam Carriage, which attracted much attention from the public and press when he drove it that year in London from Holborn to Paddington and back. However, it was particularly uncomfortable for passengers and proved more expensive to run than a conventional horse-drawn carriage and so was abandoned.

The tragedy at Greenwich

Also in 1803, one of Trevithick's stationary pumping engines in use at Greenwich exploded, killing four men. Although Trevithick considered the explosion was caused by another case of careless operation rather than design error, the incident was exploited relentlessly by his competitors and promoters of the low-pressure engine, Watt and Boulton, who highlighted the perceived risks of using high pressure steam. Trevithick's response was to incorporate two safety valves into future designs, only one of which could be adjusted by the operator. The adjustable valve comprised a disk covering a small hole at the top of the boiler above the water level in the steam chest. The force exerted by the steam pressure was equalised by an opposite force created by a weight attached to a pivoted lever. The position of the weight on the lever was adjustable thus allowing the operator to set the maximum steam pressure. The second valve was in fact a lead plug critically positioned in the boiler just below the minimum safe water level. Under normal operation the water temperature could not exceed that of boiling water and therefore kept the lead below its melting point. In the event of the water running low, once it had exposed the lead plug the cooling effect of the water was lost and the temperature could rise sufficiently to melt the lead. This would release steam into the atmosphere, reduce the boiler pressure and provide an audible alarm in sufficient time for the operator to damp down the fire and let the boiler cool naturally before any permanent damage could occur.

The "Pen-y-Darren" locomotive

"Pen-y-Darren Locomotive"
Line drawing of the locomotive
Type and origin Power type Steam Builder Richard Trevithick Build date 1804
Specifications Configuration: ​  • Whyte 0-4-0

Trevithick's 1804 locomotive. This full-scale replica of steam-powered railway locomotive is in the National Waterfront Museum, Swansea

In 1802 Trevithick built one of his high pressure steam engines to drive a hammer at the Pen-y-Darren Ironworks in Merthyr Tydfil, South Wales. With the assistance of Rees Jones, an employee of the iron works and under the supervision of Samuel Homfray, the proprietor, he mounted the engine on wheels and turned it into a locomotive. In 1803 Trevithick sold the patents for his locomotives to Samuel Homfray.

Homfray was so impressed with Trevithick's locomotive that he made a bet with another ironmaster, Richard Crawshay, for 500 guineas that Trevithick's steam locomotive could haul 10 tons of iron along the Merthyr Tydfil Tramroad from Penydarren to Abercynon, a distance of 9.75 miles (16 km). Amid great interest from the public, on 21 February 1804 it successfully carried 10 tons of iron, 5 wagons and 70 men the full distance in 4 hours and 5 minutes, an average speed of approximately 2.4 mph (3.9 km/h). As well as Homfray, Crawshay and the passengers, other witnesses included Mr. Giddy, a respected patron of Trevithick and an 'engineer from the Government'. The engineer from the Government was probably a safety inspector and particularly interested in the boiler's ability to withstand high steam pressures.

The locomotive itself was of a very primitive design. It comprised a boiler with a single return flue mounted upon a four wheel frame. At one end, a single cylinder with very long stroke was mounted partly in the boiler, and a piston rod crosshead ran out along a slidebar, an arrangement that looked like a giant trombone. As there was only one cylinder, this was coupled to a large flywheel mounted on one side. The rotational inertia of the flywheel would even out the movement that was transmitted to a central cog-wheel that was, in turn connected to the driving wheels. It again used a high pressure cylinder without a condenser, the exhaust steam was sent up the chimney and possibly used to assist the draught through the fire, increasing efficiency even more.

File:GBP2coinTrevithick.jpg

Reverse of £2 coin commemorating Trevithick's locomotive.

The bet was won. Despite many people's doubts, it had been shown that, provided that the gradient was sufficiently shallow, it was possible to successfully haul heavy carriages along a "smooth" iron road using the adhesive weight alone of a suitably heavy and powerful steam locomotive. Trevithick's was probably the first to do so; however some of the short cast iron plates of the tramroad broke under the locomotive as they were intended only to support the lighter axle load of horse-drawn wagons and so the tramroad returned to horse power after the initial test run.

Homfray was pleased enough. He had won his bet and the engine was placed on blocks and reverted to its original stationary job of driving the hammers.

The "Newcastle" locomotive

Christopher Blackett, proprietor of the Wylam colliery near Newcastle, heard of the success in Wales and wrote to Trevithick asking for locomotive designs. These were sent to John Whitfield at Gateshead, Trevithick's agent, who built what was probably the first locomotive to have flanged wheels.. Blackett was using wooden rails for his tramway and, once again, Trevithick's machine was to prove too heavy for its track.

"Catch Me Who Can"

Trevithick's steam circus

In 1808 Trevithick publicised his steam railway locomotive expertise by building a new locomotive called 'Catch me who can', built for him by John Hazledine and John Urpeth Rastrick at Bridgnorth in Shropshire, similar to that used at Penydarren and named by Mr. Giddy's daughter. This was probably Trevithick's third railway locomotive after those used at Pen-y-darren ironworks and the Wylam colliery. He ran it on a circular track just south of the present day Euston Square tube station in London, whose site in Bloomsbury has recently been identified archaeologically as that occupied by the Chadwick Building, part of University College London. Admission to the "steam circus" was one shilling including a ride and it was intended to show that rail travel was faster than by horse. This venture also suffered from weak tracks and the interest from the public was limited. Trevithick was disappointed by the response and designed no more railway locomotives. It was not until 1812 that twin cylinder steam locomotives, built by Matthew Murray in Holbeck, successfully started replacing horses for hauling coal wagons on the edge railed, rack and pinion Middleton Railway from Middleton colliery to Leeds, West Yorkshire.

Civil Engineering

In 1805 Robert Vazie, another Cornish engineer, was selected by the Thames Archway Company to drive a tunnel under the River Thames at Rotherhithe. Vazie encountered serious problems with water influx and got no further than sinking the end shafts when the directors called in Trevithick for consultation. The directors agreed to pay Trevithick £1000 if he could successfully complete the tunnel, a length of 1220 feet (366 m). In August 1807 Trevithick began driving a small tunnel 5 feet (1.5 m) high tapering from 2 feet 6 inches (0.75 m) at the top to 3 feet (0.9 m) at the bottom. By 23 December after it had progressed 950 feet (285 m) progress was delayed after a sudden inrush of water and only one month later, at 1040 feet (312 m), a more serious inrush occurred. The tunnel was flooded and Trevithick, being the last to leave, was nearly drowned. Progress stalled and a few of the directors attempted to discredit Trevithick but the quality of his work was eventually upheld by two colliery engineers from the North of England. Despite suggesting various building techniques to complete the project, including a submerged cast iron tube, Trevithick's links with the company ceased and the project was never actually completed. The first successful tunnel under the Thames would be started by Sir Marc Isambard Brunel in 1823, three quarters of a mile upstream, assisted by his son Isambard Kingdom Brunel (who also nearly died in a tunnel collapse). Marc Brunel finally completed it in 1843, the delays being due to problems with funding. However, Trevithick's suggestion of a submerged tube approach was successfully implemented for the first time across the Detroit River in Michigan with the construction of the Michigan Central Railway Tunnel, under the engineering supervision of The New York Central Railway's engineering vice president, William J Wilgus. Construction began in 1903 and was completed in 1910. The Detroit–Windsor Tunnel which was completed in 1930 for automotive traffic, and the tunnel under the Hong Kong harbour were also submerged tube designs.

Other projects in London

Trevithick went on to research other projects to exploit his high pressure steam engines: boring brass for cannon manufacture, stone crushing, rolling mills, forge hammers, blast furnace blowers as well as the traditional mining applications. He also built a barge powered by paddle wheels and several dredgers.

Trevithick saw opportunities in London and persuaded his wife and 4 children reluctantly to join him in 1808 for two and a half years lodging first in Rotherhithe and then in Limehouse.

Nautical projects

In 1808 Trevithick entered a partnership with Robert Dickinson, a West India merchant. Dickinson supported several of Trevithick's patents. The first of these was the 'Nautical Labourer'; a steam tug with a floating crane propelled by paddle wheels. However, it did not meet the fire regulations for the docks and the Society of Coal Whippers, worried about losing their livelihood, even threatened the life of Trevithick.

Another patent was for the installation of iron tanks in ships for storage of cargo and water instead of in wooden casks. A small works was set up at Limehouse to manufacture them, employing 3 men. The tanks were also used to raise sunken wrecks by placing them under the wreck and creating buoyancy by pumping them full of air. In 1810 a wreck near Margate was raised in this way but there was a dispute over payment and Trevithick was driven to cut the lashings loose and let it sink again.

In 1809 Trevithick worked on various ideas on improvements for ships: iron floating docks, iron ships, telescopic iron masts, improved ship structures, iron buoys and using heat from the ships boilers for cooking.

Failure & return to Cornwall

In May 1810 he caught typhoid and nearly died. By September he had recovered sufficiently to travel back to Cornwall by ship and in February 1811 he and Dickinson were declared bankrupt. They were not discharged until 1814, Trevithick having paid off most of the partnership debts from his own funds.

The Cornish boiler and the Cornish engine

In about 1812 Trevithick designed the ‘Cornish boiler’. These were horizontal, cylindrical boilers with a single internal fire tube or flue passing horizontally through the middle. Hot exhaust gases from the fire passed through the flue thus increasing the surface area heating the water and improving efficiency. These types were installed in the Boulton and Watt pumping engines at Dolcoath and more than doubled their efficiency.

Again in 1812 he installed a new 'high pressure' experimental steam engine also with condensing at Wheal Prosper. This became known as the 'Cornish engine' and was the most efficient in the world at that time. Other Cornish engineers contributed to its development but Trevithick's work was predominant. In the same year he installed another high pressure engine, though non-condensing, in a threshing machine on a farm at Probus, Cornwall. It was very successful and proved to be cheaper to run than the horses it replaced. It ran for 70 years and was then exhibited at the Science Museum.

The recoil engine

In one of Trevithick’s more unusual projects, he attempted to build a 'recoil engine' based on the famous model described by Hero of Alexandria in about AD 50. This comprised a boiler feeding a hollow axle to route the steam to a catherine wheel with two fine-bore steam jets on its circumference. The first wheel was 15 feet (4.6 m) in diameter and a later attempt was 24 feet (7.3 m) in diameter. To get any usable torque, steam had to issue from the nozzles at a very high velocity and in such large volume that it proved not to operate with adequate efficiency. Today this would be recognised as a reaction turbine.

South America

Draining the Peruvian silver mines

In 1811 draining water from the rich silver mines of Cerro de Pasco in Peru at an altitude of 14,000 feet (4267 m) posed serious problems for the man in charge, Francisco Uville. The low pressure condensing engines by Boulton and Watt developed so little power as to be useless at this altitude, and they could not be dismantled into sufficiently small pieces to be transported there along mule tracks. Uville was sent to England to investigate using Trevithick's high pressure steam engine. He bought one for 20 guineas, transported it back and found it to work quite satisfactorily. In 1813 Uville set sail again for England and, having fallen ill on the way, broke his journey via Jamaica. When he had recovered he boarded the Falmouth packet ship 'Fox' coincidentally with one of Trevithick's cousins on board the same vessel. Trevithick's home was just a few miles from Falmouth so Uville was able to meet him and tell him about the project.

Trevithick leaves for South America

On 20 October 1816 Trevithick left Penzance on the whaler ship Asp accompanied by a lawyer Page and a boilermaker bound for Peru. He was received by Uville with honour initially but relations soon broke down and Trevithick left in disgust at the accusations directed at him. He travelled widely in Peru acting as a consultant on mining methods. The government granted him certain mining rights and he found mining areas, but did not have the funds to develop them, with the exception of a copper and silver mine at Caxatambo. After a time serving in the army of Simon Bolivar he returned to Caxatambo but due to the unsettled state of the country and presence of the Spanish army he was forced to leave the area and abandon £5000 worth of ore ready to ship. Uville died in 1818 and Trevithick soon returned to Cerro de Pasco to continue mining. However, the war of liberation denied him several objectives. Meanwhile, back in England, he was accused of neglecting his wife Jane and family in Cornwall.

Exploring the isthmus of Costa Rica on foot

After leaving Cerro de Pasco, Trevithick passed through Ecuador on his way to Bogotá in Colombia. He arrived in Costa Rica in 1822 hoping to develop mining machinery. He spent time looking for a practical route to transport ore and equipment, settling on using the San Juan River, the Sarapiqui River, and then a railway to cover the remaining distance. In a biography his son wrote that Trevithick had in mind a steam-driven railway and not mule-driven.

The initial party comprised Trevithick, Scottish mining projector James Gerard, two schoolboys: José Maria Montealegre (a future president of Costa Rica) and his brother Mariano, whom Gerard intended to enrol in Highgate School, North London, and seven natives, three of whom returned home after guiding them through the first part of their journey. The journey was treacherous – one of the party was drowned in a raging torrent and Trevithick was nearly killed on at least two occasions. In the first he was saved from drowning by Gerard, and in the second he was nearly devoured by an alligator following a dispute with a local man whom he had in some way offended. He made his way to Cartagena where he met Robert Stephenson who was on his way home from Colombia. It had been many years since they last met (when Stephenson was just a baby). Stephenson gave Trevithick £50 to help his passage home. He arrived at Falmouth in October 1827 with few possessions other than the clothes he was wearing. Trevithick never returned to Costa Rica.

Later projects

Taking encouragement from earlier inventors who had achieved some successes with similar endeavours, Trevithick petitioned Parliament for a grant but he was unsuccessful.

In 1829 he built a closed cycle steam engine followed by a vertical tubular boiler.

In 1830 he invented an early form of storage room heater. It comprised a small fire tube boiler with a detachable flue which could be heated either outside or indoors with the flue connected to a chimney. Once hot the hot water container could be wheeled to where heat was required and the issuing heat could be altered using adjustable doors.

To commemorate the passing of the Reform Bill in 1832 he designed a massive column to be 1000 feet (300 m) high, being 100 feet (30 m) in diameter at the base tapering to 12 feet (3.6 m) at the top where a statue of a horse would have been mounted. It was to be made of 1500 10-foot (3 m) square pieces of cast iron and would have weighed 6000 tons. There was substantial public interest in the proposal, but it was never built.

Final project

About the same time he was invited to do some development work on an engine of a new vessel at Dartford by John Hall, the founder of J & E Hall Limited. The work involved a reaction turbine for which Trevithick earned £1200. He lodged at The Bull hotel in the High Street, Dartford, Kent.

Death

The plaque at St. Edmunds Burial Ground, East Hill, Dartford. With the words "Richard Trevithick Approximately 25ft from this wall lie the remains of Richard Trevithick. The great engineer and pioneer of high pressure steam. He died at the Bull Inn, Dartford and was carried here by fellow workers of Halls Engineering Works. To a paupers grave. Born Illogan, Cornwall April 13th 1771. Died Dartford, Kent April 22nd 1833"

After he had been working in Dartford for about a year, Trevithick was taken ill with pneumonia and had to retire to bed at The Bull hotel, where he was lodging at the time. Following a week's confinement in bed he died on the morning of 22 April 1833. He was penniless, and no relatives or friends had attended his bedside during his illness. His colleagues at Hall's works made a collection for his funeral expenses and acted as bearers. They also paid a night watchman to guard his grave at night to deter grave robbers, as body snatching was common at that time.

Trevithick was buried in an unmarked grave in St Edmunds Burial Ground, East Hill, Dartford. The burial ground closed in 1857, with the gravestones being removed in the 1960s. A plaque marks the approximate spot believed to be the site of the grave. The plaque lies on the side of the park, near the East Hill gate, and an unlinked path.

Conclusion

Professor Charles Inglis, speaking in 1933 at a lecture to the Institution of Civil Engineers to commemorate the centenary of Trevithick's death, included the following words:

"In the brief period between 1799 and 1808 he totally changed the breed of steam engines, from an unwieldy giant of limited ability he evolved a prime mover of universal application".

Memorials

Richard Trevithick's statue by the public library at Camborne, Cornwall

Today, to commemorate his achievements, a statue depicting Richard Trevithick holding one of his small-scale models stands beside the public library at Camborne.

On 17 March 2007, Dartford Borough Council invited the Chairman of the Trevithick Society, Phil Hosken, to unveil a Blue Plaque at the Royal Victoria and Bull hotel (formerly The Bull) marking Trevithick's last years in Dartford and the place of his death in 1833. The Blue Plaque is prominently displayed on the Hotel's front facade and is clearly visible to visitors to the town.

The Cardiff University Engineering, Computer Science and Physics departments are based around the Trevithick Building which also holds the Trevithick Library, named after Richard Trevithick.

See also

• List of topics related to Cornwall

References

Sources

• Burton, Anthony (2000). Richard Trevithick: Giant of Steam. London: Aurum Press. ISBN 1-85410-878-6. {{cite book}}: Cite has empty unknown parameter: |coauthors= (help)
• Hodge, James (2003), Richard Trevithick (Lifelines; 6.) Princes Risborough, Buckinghamshire HP27 9AA: Shire Publications
• Lowe, James W. (1975), British Steam Locomotive Builders. Cambridge: Goose ISBN 0900404213 (reissued in 1989 by Guild Publishing)
• Rogers, Col. H. C. (1961), Turnpike to Iron Road London: Seeley, Service & Co.; pp. 40-44
• Kirby, Richard Shelton. Engineering in History. New York: Dover Publications Inc. ISBN 0486264122. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)

External links

• Richard Trevithick 1771-1833 (a page from the Trevithick Society website)
• Richard Trevithick on the Spartacus Educational website
• A replica of the London Steam Carriage visits Brooklands
• The Penydarren Locomotive, on the Spartacus Educational website
• Old Merthyr Tydfil: Richard Trevithick & Penydarren Locomotive – Historical Photographs of the Penydarren Locomotive
• Portuguese written article about Trevithick
• The Camborne ‘Trevithick Day’ Website
• The Dartford Town archive
• The history of 'Harveys of Hayle'
• Cornwall Record Office Online Catalogue for Richard Trevithick
• Contributions to the Biography of Richard Trevithick - Richard Edmonds, 1859
• Bicentenary of Trevithick's 'Puffing Devil' run up Camborne Hill, 1801 – (photo sequence)
• www.steamcircus.info - Compilation of research on the exact location of Steam Circus and some new ideas
• Trevithick bicentenary