By the 1760s steam power in the form of Newcomen engines had been around for more than half a century without radically changing the power source of most manufacturing; put in context, that is like us still using the room-sized computers of the 1960s to carry out a few specialist tasks. It was the series of adaptations devised and brought in by Watt, encouraged by his backer Matthew Boulton, that put steam power within reach of every factory and mill. This allowed mechanised industry to shed its reliance on water power and relocate from isolated valleys with fast-flowing rivers to towns and cities, coalfields and iron-mining districts. The resulting double concentration of industrial production – into large factories located in specific regions – changed the nature of work and human society. More than that, Watt’s demonstration that steam could be an efficient and effective power source led directly to the development of steam locomotives and the advent of the powered economy.
James Watt was born in 1736 in the town of Greenock, a seaport on the outer estuary of the Clyde. At that time the Clyde region was, even by the standards of the day, lacking any significant industrial development. The main occupations were fishing and farming, with shippers carrying on a steady trade with Ireland and a growing trade with the Americas. The Clyde had not yet been deepened to allow ships access to Glasgow, then a city of 12,000 inhabitants described by Daniel Defoe in 1724 as ‘the best built city in Britain, London excepted’.2 The Act of Union in 1707 gave Scottish towns access to English markets and to international trade through growing British sea power; by law all colonial trade passed through Britain and, though the lucrative Atlantic trade was still in its infancy, the west of Scotland was to benefit mightily.
Although Greenock was a small town of around 3,000 inhabitants, it had enough trade to support Watt’s father James, who trained as a wright or carpenter before becoming a house- and shipbuilder, ship’s chandler and merchant. James Watt Jnr excelled at mathematics at the local grammar school but his education was underpinned by the time he spent in his father’s workshop. Here, in the words of his biographer George Williamson, he would have seen ‘the carving of ships’ figure-heads, the making of gun-carriages, of blocks, pumps, capstans, dead-eyes . . . the adjusting and repairing of nautical instruments [and] . . . the first Crane made at Greenock, for the convenience of the Virginia tobacco ships then frequenting the harbour’.3
In view of Watt’s practical ingenuity and dexterity the value of this experience can hardly be overestimated; Watt is the great example of the eighteenth-century inventor – a third-generation artisan steeped in the experiences of the professional workshop, with enough education to enhance his practical skills. After James left school he was given a bench in his father’s shop, which he used for making models and helping to repair instruments. After his mother’s death in 1753 the young man went to Glasgow in search of work as an instrument-maker. In need of formal training Watt was drawn to London, the world centre for making barometers, thermometers, balances, forceps, armillary spheres and all manner of technical and scientific equipment. So in 1755 Watt made the twelve-day journey south; by this time he was too old to start an apprenticeship, and was fortunate to find a master willing to provide a short, intense training.
Watt left London the following summer with a copy of the Frenchman Nicolas Bion’s 1709 manual The Construction and Principal Uses of Mathematical Instruments (translated into English in 1723) and set up shop in the precincts of Glasgow University, styling himself ‘Mathematical-instrument-maker to the University’. While Scotland may have been in the infancy of its economic growth, its universities were highly advanced and the curricula were far more scientifically based than England’s. Watt was something of an autodidact: he never went to college but learned German and Italian for his work and acquired enough mathematics to hold his own with academically trained scientists.
Watt made little money in his time in the university grounds but he did make useful friends, including Joseph Black, professor of chemistry, and the noted scientist and philosopher John Robison. Watt travelled to London again in August 1759 to drum up trade and his business began to flourish when he received the financial support of one John Craig, who became his partner. He moved his shop to bigger premises in the Saltmarket and, under his arrangement with Craig, was paid £35 a year and half the profits of the partnership.
James Watt
We know that around this time Watt was carrying out experiments with steam. In 1761 he took a device known as a Papin Digester – a round boiler with a narrow tube in the top for escaping steam – and fitted a piston in the form of a syringe to the top. A steam cock was put between the boiler and the syringe to allow steam to be diverted; when it was allowed into the syringe, the piston could lift a weight of fifteen pounds. But rather than encouraging Watt, the pressure he had generated made him fearful of the dangers of steam under pressure and he abandoned that line of enquiry.
On 1 December 1763 an advert in the Glasgow Journal read: ‘James Watt has removed his shop from the Sautmercat to Mr Buchanan’s land on the Trongate where he sells all sorts of mathematical and musical instruments, with variety of Toys [iron and steel ornaments and goods] and other goods.’ This was a settled and productive time for Watt; he invested in the nearby Delftfield Pottery and in 1764 he married his cousin Margaret Miller. In 1765 he worked with Joseph Black on a new way of making soda by treating lime with seawater; this came to naught but it brought Watt into contact with John Roebuck, an industrial entrepreneur with many connections.
Watt, then, was a man with a business to run and with interests and contacts in a variety of fields. Then, an incident in the university brought his mind back to the phenomenon of steam power. Some time in the academic session of 1763–4 Professor John Anderson, tutor in natural philosophy, brought Watt the scale model of a Newcomen engine, made by Jonathan Sisson of London. The engine would not run more than a few strokes and Anderson asked Watt to investigate its malfunctioning.
While Watt was typical in many ways, he was also exceptional. Even the most adept artisan innovators of his time were essentially interested in solving practical problems through experience and trial and error; Watt, on the other hand, combined the skills of a practical artisan engineer with the inquisitiveness of a scientific investigator. When presented with the Newcomen engine he began to examine the properties of steam: its volume relative to water (which he got roughly right); the heat needed to convert a body of water to steam; and the effects of a vacuum on the boiling and condensing point of water (he discovered that condensation takes place at a lower temperature and therefore the engine cylinder had to be cooled well below 212ºF). Watt mulled over the workings of the engine and experimented with using different liquids other than water, calculated how much coal was needed to convert one gallon of water to steam, how much cold water was needed to condense a fixed amount of steam, and so on. He later wrote:
. . . being employed to put in order a small model of a fire engine belonging to the natural phil. Class & made by Jonathan Sisson I met with considerable difficulties in the execution owing to the very bad construction of some of its parts but having at last overcome all difficulties I was surprised at the Immense Quantity of fuel it consumed in proportion to its Cylinder which was only 2 in. dia. & which I imputed to the heat lost thro the Metallic Cylinder. Mr Robison being now returned it was hinted in some of our conversations together that if the Cylinder was made of wood it would not occasion the loss of so much heat being less susceptible of heat or cold than Mettals.4
Watt saw, as others had before him, that the engine’s principal inefficiency came from the necessity to have hot steam enter the cylinder which then had to be cooled in order to condense in the same cylinder in every cycle. But while others tried to improve this process through better use of cooling jackets, the injection of water under pressure or, in Robison’s case, different materials, Watt came to realise that a more radical solution was needed. By legend and by his own account (told to the historian Robert Hart
fifty years later), the revelation came to him one day in the spring of 1765, while walking across Glasgow Green (see here).
Watt decided that the only way to create an efficient engine was for the steam to condense in a separate vessel – a so-called cold condenser. This would obviate the need for the main driving cylinder to be heated and cooled in each cycle; the main cylinder could remain hot, which would require less fuel and create higher efficiency. Though other inventors saw the heating and cooling of the cylinder as one drawback of the Newcomen engine, they had not regarded it as the principal difficulty to be overcome in improving the efficiency of the engine. Watt, in contrast, isolated this as the overriding problem, and was willing to sacrifice the simplicity of the Newcomen engine in the search for a solution. While the attachment of a cold condenser made the engine more complex, requiring a higher level of engineering, Watt was convinced that it would repay these difficulties.
Watt immediately set about making a model engine with two brass cylinders: one upside down with a piston inserted at its lower end, and connected by a pipe to a second cylinder (to act as the cold condenser) with an air pump attached: the second cylinder was submerged in cold water and had cold metal ‘straws’ running its internal length. Each cylinder was about ten inches long. Watt set his boiler going and fed steam into the first cylinder; the piston remained at the bottom of the cylinder. He then closed the steam cock and opened the valve on the pipe connecting the two cylinders, before activating the air pump that drew the air out of the second cylinder which in turn pulled the steam out of the first cylinder. The steam then immediately condensed around the cold metal straws creating a vacuum in both cylinders and causing the piston in the first cylinder to rise. When he attached a weight to the bottom of the piston, Watt found that his engine, which had a cylinder capacity of around one pint of water, could lift the equivalent of two gallons.
Watt’s engine: Based on the same principles as the Newcomen engine, Watt added a separate condensing cylinder [h] which necessitated an air pump [i] to draw steam into the condenser from the main cylinder [a]. The main cylinder could then remain hot throughout the cycle. The boiler is not shown in this drawing.
In April 1765 Watt wrote to his friend James Lind, ‘I can think of nothing else but this Machine. I hope to have the decisive tryal before I see you.’5
By the summer Watt had convinced himself that his idea of a separate condenser could deliver practical results; the next step would be to build a full-scale engine, but for that he needed financial backing. He now approached John Roebuck. The son of a Sheffield cutler, educated at the Dissenting Academy in Northampton and trained as a doctor in Edinburgh, Roebuck was a technical man. In the 1740s he had devised a new method for making sulphuric acid and opened large chemical works in Prestonpans near Edinburgh; in 1759 he had also set up the Carron ironworks near Falkirk with his partners, and he held a patent for a method of making bar iron. Roebuck agreed to pay off Watt’s debts to Joseph Black, who had sponsored Watt’s investigations, and to fund the expenses of building a machine that would, Watt promised, halve the fuel required by a steam engine; in return Roebuck would take two-thirds of the profits.
Progress for the next two years was frustratingly slow. Watt got as far as making a full-scale experimental engine in a cottage in the grounds of Roebuck’s property Kinneil House, but getting it to work properly was extremely difficult. The new engine required much greater accuracy in the construction of the cylinder and piston in order to maintain an adequate seal. Newcomen had used a layer of water lying on top of a leather collar, but this was impractical for Watt’s cylinder which needed to remain hot at all times. The search for a substance that would seal the piston effectively continued for months. In addition, a cylinder made for the engine at the Carron works proved to be wholly inadequate. Watt became dispirited at the poor quality of components that were available, particularly as he needed to build an engine that others would be able to replicate.
There was a further delay while Watt worked on methods of transferring the power from the piston to where it was needed. Instead of using a balanced beam he explored two different ideas. Firstly he saw that if he turned the engine upside down the piston could operate the rods directly, without the need for a beam. But the engine would need to be a so-called reciprocating engine in order to make the cycle work. More ambitious still was his idea for a rotary engine, or steam wheel – essentially a proto-steam turbine. Although Watt worked on these two ideas for about two years, they were too advanced for the engineering of the time, and he decided to return to the balanced beam.
While Roebuck was paying the expenses for the construction of a prototype engine, Watt still needed to make a living. In the mid-1760s canals were the new boom industry, so in the summer of 1766 this multi-talented man set up as a canal surveyor. His report of a survey for a canal between the Firth of Forth and the Firth of Clyde was published in 1767; he also travelled to London as part of a campaign to win approval for the scheme, but it was refused, much to Watt’s disappointment.
For the next few years Watt continued to earn a living from surveying, while intermittently working on the Kinneil engine. Not surprisingly he was being badgered by Roebuck to devote more time to the latter: ‘You are letting the most active part of your life insensibly glide away. A day, a moment, ought not to be lost. And you should not suffer your thoughts to be diverted by any other object, or even improvement of this, but only the speediest and most effectual manner of executing one of a proper size according to your present ideas.’6
By late 1768 Watt’s work on the steam engines had developed to such a degree that Roebuck decided it was time to apply for a patent. This would protect his investment and help to bring earnings when the engine was complete. Roebuck put up the money to register a patent (around £120) and Watt travelled to London to receive patent No. 913 for ‘A new invented method of lessening the Consumption of Steam and Fuel in Fire Engines’, which was sealed on 5 January 1769.
On his return journey Watt called at Birmingham where he met the man with whom he was to change the face of Britain. Matthew Boulton’s ostensible occupation was toy-maker – a word that described a whole range of activities. According to a contemporary reference book:
. . . these Artists are divided into several branches as the Gold and Silver Toy Makers, who make trinkets, Seals, Tweezer and Tooth Pick cases, Smelling Bottles, Snuff Boxes and Filligree work, such as Toilet, Tea Chests, Inkstands &c. The Tortoiseshell Toy maker makes a beautiful variety of the above and other articles; as does also the steel; who make Cork screws, Buckles, Draw and other boxes; Snuffers, Watch Chains, Stay Hooks, Sugar knippers &c. and almost all these are likewise made in various metals.7
In 1759 the Birmingham toy trade employed 20,000 people. The city grew from 15,000 in 1730 to 35,000 in 1760 and 70,000 by 1800. Distance from major rivers had pushed its tradesmen towards small-scale metal-working; the toy trade was the lifeblood of Birmingham and Boulton was at its heart.
Boulton was not a Nonconformist but, through lack of a local grammar school, he was educated at a Dissenting Academy in Deritend. His father had been a buckle-maker and within two years of leaving the academy Boulton had invented a method of inlaying enamel into buckles. He became a partner in his father’s successful business and also married into money. In the 1750s and early 60s he expanded his fortune further.
Like Watt, Boulton was a practical man with a strong technical basis to his thinking. In 1761 he and his partner John Fothergill had built the Soho Manufactory on heathland north of Birmingham.8 Unusual for the city, which was the home of the small workshop, at its heart was a space with around 600 employees, powered by a waterwheel. Boulton was both an artisan innovator and a good salesman who attracted customers from across the world; in the 1760s and 70s his firm received orders from cities across France, Germany, Austria and as far away as Turkey.
* * *
A Tea-Kettle Business
‘There was a story curren
t in my earlier day, which appeared generally credited, that [Newcomen] conceived the idea of motive power to be obtained by steam, by watching his tea-kettle, the top or cover of which would frequently rise and fall when boiling.’
A. H. Holdsworth, Dartmouth, the Advantages of its Harbour as a Station for Foreign Mail Packets (1841)
‘An excellent example of our wrong thinking about the past is the stubborn persistence of the legend that the youthful James Watt “discovered” the power of steam by observing the lifting lid of a kettle as it boiled on the hearth of his home in Greenock. A precisely similar legend about Thomas Newcomen was once current in Dartmouth.’
L. T. C. Rolt, Thomas Newcomen:
The Prehistory of the Steam Engine (1963)
‘When John Wilkinson, the great iron-founder who bored the cylinders for Watt’s engines, referred to the activities of a rival engineer as “a tea-kettle sort of business” was he being witty or just careless in his phraseology? Watt in his notebook of steam experiments at Doldowlod drew attention to the common “tea-kitchen” as the best boiler ever designed, and pointed out that we owed this invention to the Chinese. He himself quite commonly used a tea-kettle in his experiments, sometimes securing the lid with oatmeal porridge, and in the very notebook mentioned above there is a little sketch of a kettle in Watt’s own hand being used in an experiment which led to his observing for himself the phenomenon of latent heat. The story about Watt as a boy sitting in the inglenook holding a spoon to the steam issuing from the kettle and watching the vapour condense derives from his cousin, Mrs Marion Campbell, who was his playmate when he was a child. Thus the myth which has so often been ridiculed by historians has, as other myths have, a basis in fact, and we merely need to sift the truth from the falsehood. The “tea-kettle sort of business” in which Watt himself engaged led to the transformation of the Western industrial scene, and it seems to me no accident that out of everyday articles and experiences of life a man of genius may derive lessons of universal importance. In middle life Watt used a seal which portrayed a human eye and the single word “OBSERVARE”. This was the keynote of his life.’
Iron, Steam & Money Page 11