William Murdoch - Britain's Most Underrated Engineer?

Scottish engineer William Murdoch is famous for inventing gas lighting. He spent most of his career working for Boulton & Watt - he is the leftmost of the three on the Birmingham statue above. If, as some claim, he made many of the inventions usually ascribed to James Watt, he has to be Britain's most underrated mechanical engineer. We intend to investigate his bona fides, then tour the places that he lived and worked.

Little is known of Murdoch's early life, other than that he was born in Lugar, Ayrshire, that he went to school nearby in Old Cummock and Auchinleck where he excelled at maths, and that his father was a millwright. He must have gained some practical engineering skill helping in his father's workshop, because he seems to have hit the ground running at B&W. He claimed to have built an elliptical chuck of his own design for a wood turning lathe, which he used to turn a wooden hat that he wore for his interview at B&W. Boulton said that he was impressed enough by this hat to employ Murdoch on the spot, although a recommendation from their mutual acquaintance James Boswell probably helped.

After just one year at the Soho factory, Murdoch was being treated as Chief Engineer. When faced with a tricky problem in the foundry, Watt sent for Murdoch: "If William Murdoch is not at home he should be sent for immediately as he understands the patterns, and care must be taken to avoid mistakes of which our engine shop has been too guilty.”

After two years at the Soho factory, Murdoch was dispatched to Cornwall as 'Senior Engine Erector' with responsibility for constructing and maintaining the B&W steam engines being used to pump water out of Cornwall's tin mines. Watt was there too. He was doubtless a valuable engineering mentor, but he was hopeless with money. In effect, Murdoch took on the role of Regional Account Manager for B&W's most important and most profitable market sector. Quite a responsibility for someone still only 24. It shows the faith that Boulton and Watt had in him. Boulton said as much in a letter to Watt: “I think Wm. Murdock a valuable man and deserves every civility and encouragement”. When Watt returned to Soho in 1781, Murdoch effectively took on the role as Regional Chief Engineer as well, and held both posts for the next 17 years.

James Watt's famous patent covered an enhancement to the standard Newcomen steam engine whereby steam is condensed in a separate chamber. It made Watt's steam engines more than twice as fuel efficient as the best of the Newcomen alternatives and it allowed Boulton to come up with an innovative pricing system. B&W provided, installed and maintained their steam engines for free, then charged one third of the fuel savings over an equivalently powerful Newcomen engine. Coal was scarce in Cornwall and therefore expensive, so the earnings potential was promising.

B&W pricing set an incentive to minimise manufacturing costs, maximise reliability and maximise fuel efficiency. In the early years, several major improvements were made. The first was Murdoch's 'Double D Slide valve', patented in 1781, which automatically opened the steam valve via a connection to the exhaust shaft, thereby improving the engine's timing accuracy and efficiency. Next came the 'Double Acting Engine', with condensers on both sides of the piston head. The motion relied on Murdoch's Double D Slide valve and Watt's elegant 'Parallel Motion' linkage.

Over the first five years, all B&W steam engines were reciprocating, useful only for pumping water. Most were used to pump water out of mines. By 1780, the market for mine pumping engines was getting saturated and former B&W employees were driving down prices by setting up in competition. B&W were making close to zero profit. But a new opportunity beaconed. James Pickard adapted Newcomen engines for rotary motion by linking the piston to a crankshaft. Rotary engines were far more adaptable, able to replace water wheels as a power source for mills, belts, chains and machines. And a rotary steam engine did not need to be near running water. It meant static steam engines could be used on farms and that factories could be built outside of towns. The potential market was gigantic.

Pickard had a patent. He suggested a cross license, allowing B&W to use his crankshaft if they allowed him to use the separate condenser. Boulton encouraged Watt and Murdoch to come up with a crankshaft alternative. In 1781, Murdoch devised the beautifully elegant 'Sun and Planet' gear (like the gear above on the Verdant steam engine in Dundee). It transformed B&W's fortunes. Subsequently, the majority of B&W's sales and nearly all their vaste profits came from rotary engines. Disappointingly, few of them survive. As soon as Pickard's patent expired, Sun and Planet gears were immediately replaced by crankshafts.

In 1780, Murdoch built a workshop and foundry near his house in Redruth. It was used to make replacement parts for B&W engines during the day. Murdoch used it for experiments in his spare time. In 1784, one of these experiments was the 'Oscillating Steam Engine', the simplest possible steam engine. It has found many uses over the years, although none in Murdoch's lifetime as far as we know.

Murdoch moved onto the steam carriage. He never said whether he devised the concept himself or whether he was prompted by someone else. We suspect the latter. Cugnot had got a steam powered vehicle working in France in the 1770s. It is feasible that Boulton, who always had an eye on new business opportunities, heard about it and told him. James Watt is a more likely source. His original interest in steam engines came from a discussion with John Robison in 1759 where Robison told him of his idea for a steam carriage and encouraged Watt to build it for him. We guess this came up in conversation between Watt and Murdoch when they worked together in Cornwall. 

Murdock had a working model steam carriage running around his living room in 1784, four years before a patent was issued to Fourness and Ashworth. Later that year he ran a full-size carriage known as 'The Flyer' (replica above) on the streets of Redruth. Murdoch knew that low pressure engines would be too heavy for road vehicles, so he invented the high pressure steam engine for them. The Flyer incorporated a multiple shaft crank that Murdock also invented for the purpose and that is still used in modern internal combustion engines.

One of Murdoch's colleagues wrote to Boulton and Watt about The Flyer, telling them of Murdoch's optimism for the likely popularity of road vehicles. Boulton and Watt feared that Murdoch would leave B&W to develop the steam carriage independently. They somehow persuaded him to drop the project. But not before he had showed how it worked to his next-door-neighbour, Richard Trevithick. Trevithick continued development of the high pressure steam engine, eventually patenting it in 1802.

Next came Murdoch's most famous invention, gas lighting. Some say that it was an extension of experiments he had conducted on coal gas as a child. But Boulton had seen a novelty coal gas lighting system in use at the Earl of Dundonald's estate in Culross. We suspect he told Watt and Watt told Murdoch, because it was not patented. By 1792, Murdoch's house was lit by coal gas. Then he used it to light the B&W offices in Redruth. When he left Cornwall in 1798, he used it to light the B&W Soho offices. B&W started selling coal gas lighting to factories. For some inexplicable reason they ignored the lighting needs of households, offices and public spaces. It was left up to Murdoch's assistant Samuel Clegg to make his fortune by exploiting this massive opportunity.

During his years in Cornwall, Murdoch made several other important inventions. In 1785, he devised a boring machine using a crown bit to bore out pipes from wood. Then he devised a steam casing for cylinders that was cast in one piece and locked by means of a conical joint, to replace the unreliable previous practice of connecting the separate components with caulked joints. In 1791, he devised a method for condensing a yellow powder that could be used as a dye or for protecting submerged wood. As such it was a forerunner of the process used to create aniline dyes. In 1795, he reformulated 'Isinglass' - a substance used to remove impurities from beer - by replacing the horribly expensive Russian sturgeon ingredient with specially treated cheap British cod.

Most B&W inventions before 1790 were patented under Watt's name, which is why they are usually attributed to him. Murdoch's correspondence, which came to light decades after after Watt's death and too late to impair Watt's reputation, shows that he, Murdoch, devised most of them. It was not Watt's intention to hijack Murdoch's ideas. It was just that Murdoch was a B&W employee. His inventions belonged to the company. They had to be patented by an officer of the company. Watt was simply fulfilling his legal obligations. Even though it was probably unintentional, it boosted Watt's reputation at Murdoch's expense, and it muddied the waters with the Double Acting Engine, which is generally thought to be Watt's second most important invention.

James Watt definitely invented the Parallel Motion linkage for the Double Acting Engine. He said it was his proudest achievement. He never claimed to have devised the device itself, but nor did Murdoch. They worked together on product development by correspondence, because Watt was in Soho and Murdoch in Cornwall. There should be evidence of its genesis in their letters, which passed down to their families when they died. But Watt's letters to Murdoch are unclear and Murdoch's letters to Watt between 1780 and 1799 are missing. This led John Griffiths to suspect that Watt's son destroyed them to hide the evidence that Murdoch made most of the innovations that were generally attributed to his father. It is suspicious. Nothing else is missing. We guess that Griffiths is right and that the Double Acting Engine was based on an idea by Murdoch, who then worked with Watt to make a prototype.

After 1790, Murdoch negotiated a deal whereby he remained an employee yet could file patents in his own name. It was not until 1810, long after the business had been handed over to Boulton and Watt's sons, that he became a full partner.

On his return to Soho in 1798, Murdoch's mechanical engineering interests expanded, especially into pneumatic devices, and the storage and distribution of coal gas. He was never a formal member of the Lunar Society - and it was much depleted by the 1790s, through death, politics and emigration - but we guess that his burgeoning interests were fuelled by meeting or corresponding with the surviving members of the Lunar Society. His inventions included:

  • In 1799, the pneumatic message system, whereby messages in cannisters are sent through tubes by compressed air. This system became ubiquitous in offices and was still used in some retailers until cash went out of fashion in the 2000s. The last surviving working system is in Prague (picture above).
  • In 1799, the endless screw working in a toothed wheel, which he used to bore out piston cylinders
  • In 1802, the pneumatic actuator, which he used it to lift heavy castings 12 feet from the foundry to the workshop. It is still the most common type of heavy duty actuator, used for air brakes among many purposes.
  • In 1803, the steam gun and steam cannon, invented 20 years before Jacob Perkin got a patent for his 1000 shot/minute steam gun
  • In 1807, the first marine steam engine
  • In 1808, devices to make, purify and store coal gas. His storage system, for which he coined the term 'gasometer', has kept its name and is still the standard way to store unliquified coal gas and natural gas.
  • In 1810, an enhancement of his wood boring crown bit to bore out pipes in stone
  • In 1815, apparatus for heating the baths at Leamington by the circulation of water from a boiler through pipes immersed in the baths. This system was widely adopted to heat buildings and is still used to heat water tanks in domestic central heating and hot water systems.

One irony of all this is that William Murdoch is not recognised as the inventor of half a dozen of the most transformative technologies in human history, but did not invent gas lighting, the technology for which he is famous. To be fair, even if the Earl of Dundonald invented the concept of gas lighting, Murdoch made it practical and safe.

It is often said that James Clerk Maxwell invented the 20th century. William Murdoch, every bit as much, invented the 19th century. His high-pressure steam engine begat steam locomotives which transformed mobility, freight, farming, industry and mail. Railways allowed bulky fresh produce to be transported quickly, which was the main catalyst for the explosive growth of Victorian cities. His pneumatic messaging system transformed clerical business processes. His gas lighting transformed our workplaces, homes, streets and places of entertainment, extending the working day and making it safe to go out in the dark. His mechanical home comforts created an aspirational model and formed a bridge to modern housing.

Hugely successful as it was, there is a large dose of 'what might have beens' about Murdoch's pneumatic messaging system. If the telegraph had not come along, it would probably have developed into a nationwide rapid mail delivery system, which also had the ability to send small parcels. It would have been superior to anything we have today and might well have forced retailers to adopt an 'Amazon warehouse' business model 150 years ago. In the 1830s, Murdoch's protege Samuel Clegg developed pneumatic tubes and cannisters into the atmospheric railway. Working systems were installed in Dublin, Paris and Croydon. Brunel developed a prototype atmospheric railway for the South Devon Railway. Unfortunately, they all proved unreliable because of defective seals. If only someone as ingenious as Murdoch was there to look at the problem, personal transport could have bypassed the car, jumping to something far superior. Elon Musk's Hyperloop, after all, works on the same principle.

In our opinion, William Murdock is not only Britain's greatest mechanical engineer, but the greatest by a wide margin. Brunel and the Stephensons were really civil engineers that dabbled in mechanical engineering. Watt's only significant mechanical engineering achievement was the separate condenser, which was technically simple and only used for 30 years. If it had never been invented, the main consequence would have been temporarily reduced profits at the leakier mines. Less temporary than one might think too, because Watt held back high pressure steam engines and compound steam engines by at least 10 years. Faraday is probably Murdoch's biggest rival. We discuss this elsewhere. In summary, we think Murdoch's high pressure steam engine had more impact than Faraday's dynamo at the time of their deployment, and that Murdoch made lots of other mechanical engineering innovations whereas Faraday concentrated on scientific discoveries.

Our main interest is in momentousness, by which we mean lasting beneficial impact. It incorporates the chains of influence that lead to beneficial innovations and achievements. There is an argument that James Watt can take credit for all of Murdoch's achievements because most of them were made while he worked for Boulton and Watt, and most of the rest came through his association with the Lunar Society, to which he would have been introduced by Boulton and Watt. We take the opposite view, that Boulton and Watt would not have been commercially successful if Mathew Boulton had not been such a brilliant and loyal employee. Although it is true that Boulton and Watt gave Murdoch his break, it is not enough for them to take credit for his achievements. We are convinced that Murdoch succeeded despite being held back by Boulton's financial self-interest and by Watt's conservatism. If so, he is clearly Britain's most momentous mechanical engineer.

William Murdoch tour

Murdoch was born in Bello Mill Farm, Lugar in Ayrshire. He attended Old Crummock Kirk school until the age of ten, then progressed to a school in Auchinleck. Neither of these places survives. It is said that Murdoch experimented as an adolescent in a cave beside the River Lugar. It is 90m upstream on the north bank of the Lugar.

Murdoch walked to Soho Manufactory near Birmingham just before his 23rd birthday. He was interviewed by Matthew Boulton and given a job on the spot. He worked in the pattern shop at Soho Foundry for two years. The manufactory is long gone but the foundry is still there. It is now a weighing machine factory belonging to Avery. Murdoch Cottage, where he lived when he returned to Soho in 1798, is inside. Apparently, there is also a small museum, but it was closed when we went.

Murdoch moved to Redruth in 1779. He lived at Murdoch House (below) for the next 19 years. This was where he installed the world's production first gas lighting system. It is a museum now.

Murdoch returned to Smethwick in 1798. He lived in the cottage that is now inside the Avery factory. Nothing else remains from his time here. Matthew Boulton's home, named Soho House (below), survives. Murdoch would have been a regular visitor and would have attended Lunar Society meetings here.

The gold-plated memorial statue of Boulton, Watt and Murdoch (top) usually stands in Centenary Square but it has been temporarily removed to make way for tramworks. Apparently, it will be returned once the work is complete.

The only place to find out about Murdoch's work on coal gas production, storage and lighting is the Fakenham Gas Museum (retorts above).

There are two replica Flyers. One is in Mosley Toy Museum. The other (above) is in the middle of Tolgus Roundabout, adjacent to the smaller of the two Tescos in Redruth.

There is a bust of Mudoch (second left) in the Hall of Heroes at Wallace National Memorial, right next to James Watt. He is buried in the churchyard of St Mary's, Handsworth, where there is another bust of him, next to busts of Boulton and Watt.