In 1777 Watt took the four-day journey from Birmingham to Cornwall to oversee the installation of engines at Ting Tang and Wheal Busy. The Cornish mines and their miners were something to behold. The mining country around Redruth and Camborne was a bleak site with spoil-heaps, piles of rubble, sheds, windings and tracks showing evidence of the centuries of exploitation of the rich seams of copper and tin. The miners bought ropes and candles off the mine-owners and were paid for the ore they brought to the shaft. The shafts themselves could be between 500 and 1,000 feet deep and were reached by ladder, with the baskets of ore being hauled to the surface by horse-powered winches. The miners’ wives and children then smashed the ore with hammers into grains ready for treatment or transport. The ore was taken in sacks to the auction market in Redruth, from where it would be transported to the coast and on to Swansea and Bristol for smelting. Gunpowder was used to loosen the ore beneath ground, increasing the already terrifying risks of rockfalls and flooding; Cornish miners did not work much beyond thirty.
By the time of Watt’s first visit in 1777 there were around sixty Newcomen engines working in Cornwall. While the mine-owners might have been keen on Watt’s engine design, the local engineers – including Richard Trevithick Snr – were suspicious of Watt’s claims and Watt also found that the existing engines were not kept in good repair. Jonathan Hornblower Snr told Watt that Cornwall had ‘good Engine smiths . . . & some bad ones (all of them love drinking too much)’.17
Watt was determined to overcome any suspicions about the engines’ performance by measuring the strokes – he had devised a counter to assess the premium to be paid – the weight of water pumped and the amount of fuel used. He calculated that the best duty from his engines came from a cylinder of smaller size than that employed in the Newcomen engines.
In 1777 Boulton & Watt took on a young Scottish engineer named William Murdoch, who was sent to Cornwall and soon became the best engine fitter in the land. Murdoch was to play a vital role in the future of steam power.
By September 1777 the Wheal Busy engine was working. Boulton & Watt then received an order for a sixty-three-inch engine for Tregurtha Downs at Marazion, but Richard Trevithick Snr, at a public meeting, accused Watt of inventing the fuel savings: ‘I was so confounded with the impudence, ignorance, and overbearing manner of the man,’ wrote Watt, ‘that I could make no adequate defence, and indeed could scarcely keep my temper, which, however, I did to a fault.’ Despite the engineers’ hostility, the mine-owners recognised the efficiency savings and ordered more Watt engines as fast as they could be made. Cylinders continued to be supplied by John Wilkinson, valves and nozzles were produced at the Soho works, with other parts made locally, and the on-site construction supervised by Murdoch or Watt. Cornwall was conquered.
With the engine in such demand in the West Country and elsewhere these should have been prosperous days for the firm of Boulton & Watt. But in 1778, when a recession hit the English economy, the firm was ill prepared. Success brought cash-flow problems: it cost hard cash to employ men and to buy components, while royalties from licences came in much later, and often had to be chased up. As Boulton couldn’t raise capital through shares, he approached Cornish banks and raised capital against future earnings. He also borrowed £17,000 against the engine patent and kept harassing Watt to build more engines. At one point Boulton had to reduce his workforce from 700 to 150.
News of the improved engine soon spread through Britain’s industrial community. In 1781 Samuel Walker, ironmaster of Rotherham, wrote to Boulton & Watt:
We have some Works upon a River which in general supplies us with Water. In order to make up this defect, in some measure, we are intending to build a Fire Engine, either in the old or common manner or under the Sanction of your Patent . . . We have coal of our own getting laid down at the Works at about 2¾d cwt and are thinking of a Cylinder 36 or 43 inches diameter and eight foot stroke and suppose we may work the engine 3 to 6 months in the Year according as the Seasons are wet or dry.
Watt’s reply in May 1781 showed that the market in areas where coal was cheap was still hard to crack, principally because royalties were paid to the firm on the basis of how much fuel had been saved by replacing the Newcomen engine: ‘The Coal Mines in Yorkshire will not pay us for our attention on that business and we have declined engine orders where Coals are of less value than 4s or 5s a ton.’
Nevertheless Boulton & Watt were happy to supply an engine to the Rotherham firm. Samuel Walker’s diary records: ‘Pull’d down two shops to make room for a new Fire Engine and rebuilt ’em in the same yard: built and cover’d in a new fire engine house (this is a very heavy job).’ And by September: ‘The Fire Engine completed to blow our three furnaces and began to work this month.’18
By the early 1780s, therefore, Boulton & Watt managed to navigate the financial perils of industry while gradually attracting more customers. But they remained restricted. Their engines still used the same principle of the balanced beam that Newcomen had designed in 1712 and, like Newcomen engines, they were mostly used for pumping water and blowing blast furnaces. Boulton realised that steam engines needed to be able to imitate the rotational power of waterwheels if they were to be of use to other industries. He had been pressing Watt to build engines with a rotational motion for two years, and in June 1781 he betrayed his impatience in a letter to Watt, who by now spent much of the year in Cornwall: ‘The people in London, Manchester and Birmingham are steam mill mad. I don’t mean to hurry you but I think in the course of a month or two, we should determine to take out a patent for certain methods of producing rotative motion from . . . the fire engine . . . There is no other Cornwall to be found, and the most likely line for the consumption of our engines is the application of them to mills which is certainly an extensive field.’19
Turning the motion of a beam into rotational motion seems a trivial matter – hook up a crank and flywheel and away you go. But the practice was more complex. The stroke of the engine was irregular in time and length; a short stroke might send the crank turning back while a long stroke risked pushing it out of kilter. In addition the notion that a flywheel would help to control and smooth its motion had not been fully explored. The engines were single acting, only having power in one stroke, so a counterbalance would be needed to pull the piston out each time. How could such a counterstroke be arranged?
In 1779 James Pickard, the owner of a flour mill at Snow Hill in Birmingham, asked the Bristol engineer Matthew Wasbrough to build an engine to turn the machinery in his mill. Wasbrough’s solution was a Newcomen-type engine with the addition of racks and pinions to deliver a rotational motion. When this did not work to Pickard’s satisfaction he fitted a crank and flywheel; the result was the world’s first working rotational engine. It was the flywheel that was crucial, but when Pickard applied for a patent in 1780 he instead specified a crank with a wheel with weights on it. James Watt was furious; this had been one of his ideas and he believed Pickard had stolen it through a spy in the Soho works. Watt immediately realised that he had to patent the range of devices being worked on at Soho, including the sun and planet gearing for translating linear into rotational motion, the swash plate for raising the beam of the engine, the eccentric wheel acting inside a circular yoke, and the counterweighted crank. All these patents were granted in October 1781 but there is some controversy as to the origin of the most important device – the sun and planet gearing. While Watt claimed that William Murdoch, who first built the mechanism, revived an old idea of Watt’s, others believe that it was Murdoch who invented the sun and planet system.
In March 1782 Watt was awarded a patent for a double-acting engine with each cylinder being pulled first one way then the other – the need for a counterstroke was solved and by condensing steam on each side of the piston in turn, the engine produced smooth motion and used less fuel. This required a different connection to the beam, which had to be rigid enough to be pushed – the previous motion had been pulling only, by using a flex
ible chain – while maintaining the flexibility needed to allow for the curved motion of the beam end. Watt came up with the system known as parallel motion, which was patented in 1784. As Watt later wrote: ‘Though I am not over anxious after fame, yet I am more proud of the parallel motion than of any other mechanical invention I have ever made.’20 Controversially, however, the 1784 patent also granted Watt protection for the invention of a steam carriage using ‘the elastic force of steam to give it motion’. Given Watt’s intention not to follow this course, it seems that this was a purely obstructive tactic. Watt also blocked William Murdoch from pursuing the idea within the firm, writing to Boulton in September 1786: ‘I am extreamly sorry that W. M. still busys himself with the Stm carriage.’21
Sun and planet gearing: The drive arm [x] is pushed back and forth by a traditional Watt engine; this pushes the toothed wheel [b] around the cog [a] which turns the wheel [z] thus converting linear into rotary motion.
Watt finally built a rotative engine to his own satisfaction in 1783, which was supplied to John Wilkinson to drive a steam hammer at Bradley ironworks. The next rotative engine was not constructed until the following year, as Watt was engrossed in perfecting his double-acting engine. But by the late 1780s the design had become standardised with double-acting engine, sun and planet gear, parallel motion, valves and connecting rods all being supplied to customers. Steam power had become available to any sizeable industrial concern.
The final commercial breakthrough came in 1789 when Peter Drinkwater ordered an eight-horsepower engine for his Manchester cotton mill. Cotton was the great new industry and Manchester was its commercial centre; steam power had finally arrived at the heart of industrial production. Boulton & Watt rapidly appointed a Manchester agent who in 1791 was able to report: ‘Mr Barton [manager of the Simpson cotton mill] desires me to inform you, that they intend taking down their old engine and putting one of yours in its place – They have set at present 4,000 spindles & preparation in the Mill and they mean to put 1,000 or 1,500 more in it.’22
For their beam engines Boulton & Watt charged a royalty based on the amount of fuel saved from the use of a Newcomen engine. But the rotative engine was taking them into new markets that had never used steam, so they needed a different measure of power output. People had talked about horsepower before – Smeaton commenting that his engine at Kronstadt was equal to the work of 400 horses – but in 1783 Watt quantified an engine’s power, working out by rough estimate that a horse’s strength was equal to raising 33,000 lb, one foot high, per minute. The firm would then rate their machines as, for example, a ‘20-horse engine’. Watt developed a pressure gauge to measure the power attained by his rotative engine and his assistant Southern came up with the idea of attaching a pencil and a roll of paper on which to trace the changing pressure in the cylinder over time; this allowed them to see whether the engine was performing to its proper capacity.
The firm’s horizons expanded further in 1788 when Boulton & Watt invested in Albion Mill, a huge flour mill to be built on the south bank of the Thames near Blackfriars Bridge. The firm was to supply three engines to unload wheat from barges and carry out hoisting, milling and sifting. John Rennie worked on the milling side and became a famous engineer in his own right. When the mill burned down just three years after opening arson was suspected, particularly as millers had been hostile to mechanisation, but no one was ever put on trial. Between them Boulton and Watt lost around £9,000 – a fortune at the time – showing them both to be wealthy men.
The 1786 commercial agreement between Britain and France (the Eden Treaty) opened up new possibilities for British industrialists abroad. Both countries, after centuries of restricting trade, agreed to reduce tariffs on each other’s goods. Boulton and Watt visited Paris after the French finance minister Charles de Calonne had invited the firm to tender to pump water from the Seine to Versailles. Though this never came about due to the revolution of 1789, Watt did meet France’s leading scientists including Antoine Lavoisier, Pierre-Simon Laplace and Claude-Louis Berthollet.23
Watt continued to improve his engines and in 1788 the first steam engine to employ a centrifugal governor was built at Soho. Boulton had earlier written to Watt about an old technique being used at Albion Mill: ‘for regulating the pressure or distance of the top millstone from the bed stone in such a manner that the faster the engine goes the lower or closer it grinds and when the engine stops the top stone rises up . . . this is produced by the centrifugal force of 2 lead weights.’24 Watt didn’t claim to have invented the governor but its adaptation was his final contribution to the development of the steam engine.
In 1790 Watt was prosperous enough to acquire forty acres of land on Handsworth Heath and build a substantial mansion, known as Heathfield (it was pulled down in 1927). As the prospect of the patent expiring in 1800 came nearer, Boulton realised that the firm would need to build complete engines in competition with others. In 1795 he bought land at Smethwick, only a mile or so from the Soho Manufactory, and built the Soho Foundry alongside the Birmingham and Wolverhampton canal.
By that time Boulton & Watt had become the victim of its own success: there was more demand for rotative engines than one firm could design, let alone build. Sometimes to avoid paying royalties, and sometimes out of desperation, manufacturers turned to other engine makers. In 1796 Boulton & Watt took out a writ against Hornblower & Maberley, who had taken the double-cylinder engine patented by Isaac Mainwaring and made it into a double-acting engine.25 While this was legitimate, Watt regarded the engine’s separate condenser as an infringement of his patent.
‘The rascals seem to have been going on as if the patents were their own,’ he wrote to Boulton. ‘We have tried every lenient means with them in vain and since the fear of God has no effect upon them, we must try what the fear of the devil can do.’ But Boulton was unperturbed, telling Watt: ‘If we do suffer ourselves to be pissed upon by that family we deserve to be sh–t upon. For God’s sake don’t lose a moment’s peace upon that head, but proceed, get the Engines erected & Money in our pockets.’26
But Watt was adamant and told Boulton that he ‘should not lose the battle before you fight it’. He sent James Law to spy on the engine house at Radstock colliery where Hornblower’s first engine was built, but when he couldn’t get in Watt went to Bristol to confront the owner, Major Tucker, ‘a potato-faced, chuckle-headed fellow with a scar on the pupil of one eye. In short I did not like his physiog’.27 Tucker palmed him off by saying he would look into Watt’s complaint. By this time Richard Arkwright had just lost his carding patent (which covered the preparation of cotton for spinning) in a sensational trial, and Watt was rightly nervous that his patent would also be overturned for lack of a precise specification.
The court initially found for Boulton & Watt, but Hornblower counter-sued arguing that the original patent was invalid because of its inadequate specification. This case was not settled until January 1799, when the patent was reaffirmed; by then it had only just over a year to run. Nevertheless the victory gave Boulton & Watt thousands of pounds in fees and damages, while those who had withheld regular royalty payments until the trial’s outcome was known, particularly in Cornwall, now had to pay up.
Printing press: Rotary steam power drove the mechanisation of a vast range of activities. This printing press from the 1840s has a belt drive to draw power from a steam-powered drive shaft.
Watt handed over his responsibilities at Soho to his son and lived out his final years at his estate in Wales. When he died in 1819 aged eighty-three, he was worth around £60,000 and was a famous as well as a wealthy man. By that time James Watt had given humanity a new source of mechanical energy, steam power had been adapted for use in dozens of different industries, and the economic, physical and social revolution that this brought about was beginning to take effect.
9. Richard Trevithick:Steam into Motion
NEWCOMEN AND WATT had developed steam engines that worked under atmospheric pressure and, while
these machines kick-started Britain’s conversion to a coal-based economy, they had limitations: the amount of power produced depended on enormous cylinders and pistons and, though they were great beasts capable of powering mills and huge water pumps, their size and weight meant that they remained static. The next great leap forward freed the steam engine from these shackles, put it on wheels and sent it powering across the world. The new age was announced in flamboyant and dramatic fashion on Christmas Eve 1801 when Richard Trevithick drove his Puffing Devil up Camborne Hill.1
It is no surprise that the next great breakthrough happened in Cornwall. Cornish mines had bred generations of engineers skilled and experienced in dealing with the most difficult challenges of deep mining. It was Cornwall that was the most important early market for Boulton & Watt’s engines: the county’s distance from the coal areas of the Midlands and north made fuel expensive, while the deep tin and copper mines needed machines to pump out water. But Cornish engineers were resentful of Watt’s monopoly of improved steam power and believed his extended patent prevented their own trade from flourishing.
James Watt’s steam engines followed Thomas Newcomen’s central principle of using condensing steam to create a vacuum, which then drew the piston down into the cylinder. Because the essential power came from the weight of the atmosphere working on the vacuum, these are known as atmospheric engines. William Murdoch, the brilliant engineer who was entrusted by Boulton & Watt with erecting engines in Cornwall in the 1780s, experimented with using steam in a different way. It was well known to engineers at the time that water heated in a closed vessel caused a massive build-up of pressure, which could be released through narrow tubes or valves. As we have seen, Watt believed that the use of steam under pressure was highly dangerous and unnecessary, and he discouraged Murdoch from pursuing this line. But Murdoch seems to have carried on despite this. In 1784 his colleague Thomas Wilson wrote to James Watt that Murdoch had a plan for ‘drawing carriages along the road by steam engine’ and in 1785 Murdoch built a working model of a high-pressure steam carriage.2 Another model followed in 1786 but he was discouraged by Matthew Boulton from pursuing this further and from registering a patent, which would have set him in opposition to his employers. However, in 1797 Richard Trevithick became Murdoch’s neighbour and it is likely that the two discussed steam locomotion; it is certainly possible that Murdoch showed his model to the young Cornish engineer.
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