James Watt and William Murdoch
James Watt was born on 19 January 1736 in Greenock. There is a
long ODNB biography by Jennifer Tann and
this entry only takes some of the major features from it. The expansion of
Steamindex has brought several items about Watt to attention almost
by accident and has led to this entry. Watt's interest in steam engines dated
from about 1759, when John Robison suggested that he consider the application
of steam power to road carriages and mining. But the idea was not developed
further and, on Robison's departure from Glasgow, the project was abandoned.
In the early 1760s Watt began some experiments on the force of steam in a
Papin's digester and ''formed [a model of] a species of steam engine'', but
abandoned the idea due to pressure of other work and in the belief that an
engine on the principle employed might suffer the same drawbacks as Thomas
Savery's engine namely, the the boiler might burst, the difficulty of making
joints sufficiently tight, and the loss of much of the power of the steam
on the downward stroke of the piston. Nevertheless, he was to describe this
mechanism in his 1769 and 1784 patents.
In the winter of 1763/4 Watt was requested to repair a model Newcomen engine belonging to the natural philosophy (physics) class at Glasgow University. At this time his knowledge of steam engines was largely derived from J.T. Desaguliers's A Course of Mechanical and Experimental Philosophy (1734) and B.F. De Belidor's Architecture hydraulique (1753). He set about repairing the model engine but found the boiler could not supply it with steam. Watt identified several problems, of which the wastage of steam during the ascent of the engine piston and the method of vacuum formation in which the system was cooled were two of the most fundamental. He therefore made a new model, slightly larger than the original, and conducted many experiments on it. This led him to his well-known tea kettle experiment in which he discovered the latent heat of steam while not understanding the scientific principle, though he subsequently learned the explanation from Joseph Black. The theory of latent heat underpinned Watt's experiments on the separate condenser, in which the steam cylinder remained hot while a separate condensing vessel was cold. Writing more than forty years later, he stated that, once the separate condenser was conceived, ''all improvements followed as corollaries in quick succession, so that in the course of one or two days the invention was thus far complete in my mind, and I immediately set about an experiment to verify it practically''. While in a general sense this was probably true, many practical problems remained to be solved not all of them by Watt. In 1765 and 1766 Watt erected several atmospheric engines in Scotland, probably incorporating parts made to his own designs.
Work on steam engines was displaced for over a year by civil engineering engagements, but in 1768 he recommenced trials on model engines and in the autumn of 1768 began designing a colliery engine, incorporating a separate condenser and air-pump, for Dr John Roebuck at Kinneil.
In 1768 Watt visited Boulton's Soho Manufactory in Birmingham and met Matthew Boulton (born Birmingham on 14 September 1728 and died Birmingham on 12 August 1809: ODNB biography by Jennifer Tann) and afterwards wrote: ''I explained to him my invention of the steam engine, and several other schemes of which my head was then full, in the success of which he expressed a friendly interest'' Watt must have been impressed by the scale and organization of the factory and in Boulton he met not only an able entrepreneur but also an innovator. Watt stayed with Boulton for two weeks and on his return to Glasgow in October 1768 suggested that Boulton be offered a one-third share in the patent, possibly with Dr Small.
Watt's entry into a partnership with Boulton wasd complicated by his prior involvement with Roebuck and this was only resolved by the financial failure of Roedbuck in 1772/3 (Tann covers this at length). The death of Watt's first wife in September 1773, occurring in a year of small profit for Watt, and Small's subsequent urging that he go to Birmingham led Watt to decide to leave Scotland and join Boulton at Soho in May 1774.
Boulton proposed seeking a parliamentary bill to extend the term of Watt's patent and in May 1775 the act was passed, extending the patent for a further twenty-five years (15 Geo. III c.61). The partnership between Boulton and Watt commenced a month later. Watt recorded the terms of his partnership with Boulton at the time of his second marriage, in 1776. From this it is clear that Boulton was to bear the financial risk for the expense of the 1775 act and the costs of future experiments, and be responsible for the stock-in-trade as well as keeping accounts, in return for two-thirds of the property of the invention. Watt was to make drawings, give directions, and make surveys. On his arrival in Birmingham, Watt lived in Boulton's former house in New Hall Walk but in 1777 he and his family moved to Regents Place, Harpers Hill, a substantial house near Soho. In 1790 he started to build Heathfield, a larger, attractive two-storey house, to the designs of Samuel Wyatt, in Handsworth.: this had a garret over the kitchen used as a workshop, while in the yard below there was a forge.
The partners depended heavily on the ironmaster John Wilkinson, for it was he who was capable of boring engine cylinders with greater accuracy than any other iron-founder. Even after other iron-founders had installed boring machines similar to those of Wilkinson, they seemed unable to produce goods of such consistent quality as his. In the early years of the Boulton and Watt partnership Wilkinson's advice was sought as well as sometimes given unsolicited. His interests were both as a manufacturer in the supply-chain and also as a customer for Boulton and Watt engines. Indeed, he was one of the largest single customers, installing eleven engines at his Bradley ironworks by the 1790s and at least seven elsewhere. The Coalbrookdale Company, too, was both an important customer and supplier of engine parts. It had been to Coalbrookdale that William Small had looked when seeking parts for the Kinneil engine before Watt had moved to Birmingham, and this company and its associates became Wilkinson's chief rival in the supply of engine parts. Even when the customer for a particular engine was as eminent an ironfounding company as the Walkers of Rotherham, Watt was cautious about permitting them to cast all their own engine parts.
In general, Boulton and Watt subcontracted the manufacture of parts to firms of their own choice, most of them in the midlands region. Only piston rods seem to have been forged as far afield as Whitehaven, Workington, and Rotherhithe. During the 1780s and early 1790s, while continuing to depend on subcontractors for many engine parts, Boulton and Watt increased both the range of operations and the capacity of their engine workshop at Soho Manufactory and by 1793 were making over 50 per cent by value of their engine parts.
Watt's role was largely that of development, design, and drawing, as well as working on patent specifications. He also visited customers, notably in Cornwall. The partners employed a small group of itinerant mechanics who were responsible for the erection of engines for their British customers. Skilled mechanics were in short supply and were not above exploiting their scarcity value. It was partly in order to protect the reputation of the firm that Boulton and Watt initiated a protocol of customer visits: when either of the partners or a senior employee visited an area in which they had several customers, attempts were made to inspect each engine and to offer maintenance guidance. For the term of the extended patent a significant contribution to Boulton and Watt profits was derived from the royalty imposed on users of the Watt engine. For reciprocating engines this was computed at one-third of the savings in fuel effected by Watt's engine in comparison with a Newcomen engine capable of performing an equivalent amount of work. Premiums on rotative engines were charged at £5 per horse power per year in the provinces and 6 in London. Towards the end of the term of their patent the partners usually commuted the annual royalty to a lump sum payable upon purchase of the engine.
Shortage of capital inhibited Boulton in establishing a separate engine factory, but the discovery that Wilkinson had pirated Watt's patent, together with the patent having only five and a half more years to run, coupled with the partners having extended their own repertory of engine parts, led to a quick decision in 1795 to establish a separate engine foundry. Watt seems to have played little part in the design of the foundry, which was built adjoining the Birmingham Canal near to adequate supplies of coal. It was intended that cylinders, pumps, and all other engine parts would be made there. It was also acknowledged that the partners would aim to make improvements to the engines, a task which had been more difficult while they depended on subcontracting much of the foundry work. They perceived further advantages in being able to make engines more cheaply and in a shorter time, as well as in keeping engines in stock. Thus, Soho Foundry was opened in 1796.
Watt gradually withdrew from active participation in the business, and it was managed by his son, James Watt, and Matthew Robinson Boulton. The elder Watt retired in 1800.
The engine manufacturer who could solve the problem of rotary power generation other than by means of a water-wheel in the early years of the industrial revolution was likely to reap considerable financial reward. As early as 1765 9 Watt had devised a steam wheel to generate rotary motion. Both he and, later, Boulton had in mind a hollow annular chamber mounted on a shaft, and in 1774/5 Watt laid drawings of one before a committee of the House of Commons. It is clear that a steam wheel was made and set to work at Soho in 1774, and a year later Boulton reported that another one was being developed. But in the early years of the partnership Watt was kept busy with reciprocating engines, and plans for rotary power were laid aside. Yet Boulton continued to draw attention to the opportunities, pointing out in 1776 that he could dispose of a hundred wheel engines, were they available. The opportunities were also perceived by others. Robert Cameron, an employee who later became an independent engineer, approached Boulton with an idea. Watt discouraged Boulton, and Cameron's ideas were not proceeded with. But as early as 1779 a Newcomen engine had been fitted with rotary motion at a Birmingham flour mill owned by James Pickard, who in 1780 replaced the ratchet-and-pawl mechanism with a crank patented in the same year (No. 1263). It has been alleged that the idea of the crank had been stolen from Watt and there is evidence to substantiate this, though Watt's stated reason for not patenting or developing rotary power at this time pressure of work was weak. It is more likely that he still needed to be persuaded of the usefulness of rotative power. However, under increasing pressure from Boulton he was persuaded to do so and, probably not wishing to contest the crank patent, developed, instead, ''sun and planet motion'', which was patented in 1781 (No. 1306). The firm used this mechanism on all its rotative engines until 1794, when Pickard's patent expired, and in some cases for several years afterwards, after which time it also employed the crank, which was a far more effective way of generating rotative power.
In 1782 Watt was granted a patent for several major improvements to his engine (No. 1321). Of greatest significance was rotative motion. Other improvements included the use of the expansive principle and the double-acting engine, as well as a means of connecting the piston rod and beam for use in double-acting engines. Of these improvements it was the double-acting engine that had potential application, fuel savings in the expansive engine being found, in practice, to be too small to warrant development. The rack-and-sector connection for the double-acting engine was superseded by parallel motion, which was patented by Watt in 1784 (No. 1432) together with various other improvements, including the application of steam engines to wheel carriages. Of all his inventions it was parallel motion that appears most to have pleased James Watt.
Boulton and Watt were a natural target for industrial espionage. Employees talked or were bribed, and over-curious visitors would make drawings when possible. In turn the partners were vigilant in tracking down patent infringers. Friends described new engine installations around the country, while faithful employees such as William Murdock reported on anything suspicious, particularly in Cornwall. The partners sought patent protection and privileges overseas, some form of privilege being obtained in France, Spain, and the Netherlands. Discussions were also initiated regarding patents in the United States and the Austrian empire but none was granted. The market for engines Estimates for the number of engines manufactured by Boulton and Watt for the British market during the term of their patent have varied considerably, ranging from 318 to 512. While the smaller figure is a considerable underestimate, the latter includes a number of double counts; the most likely figure is 449 engines. Demand for the Watt engine was low at first but so too was the company's capacity to produce the requisite drawings and patterns for the subcontracting of parts. Until 1783 all the engines built were reciprocating ones, but thereafter rotative engines appear in the orderbooks.
By the end of 1800 Boulton and Watt engines totalling approximately 11,205 hp had been erected in Britain at an average size of just under 25 hp per engine. A large proportion of the pumping engines sold by Boulton and Watt during the first ten years or so of their partnership was supplied to the Cornish copper and tin mines. The Cornish activities of the partners are significant for several reasons: first, for the sheer scale of their operations, both in the number and size of engines supplied to the region as well as the proportion of the partners' total profit contributed by Cornish engines; and second, because Boulton and Watt became large investors in Cornish mines to enhance demand for its engines at a period when the Cornish copper industry was subject to considerable fluctuation. Demand for Boulton and Watt engines in Cornwall was enhanced as the mines had reached a depth from which neither water engines nor the Newcomen engine could extract water adequately and consequently the mines were in danger of being flooded. Moreover, Newcomen engines consumed greater quantities of coal than the Watt engine. Thus Cornwall provided an ideal setting for a demonstration of the considerable savings in coal that Watt's engine would effect over a Newcomen engine of comparable power. Between 1777 and 1801 forty-nine Boulton and Watt engines were erected in Cornwall. During the early 1780s the proportion of Boulton and Watt's engine business accounted for by Cornwall ranged from as low as 5 per cent to as much as 80 per cent in any one year. Until 1784 all the Watt engines erected on the Cornish mines were single-acting, but in that year both the double-acting pumping engine and the rotative engine were introduced to Cornwall. In all cases rotative engines were of a lower horsepower equivalent than the pumping engines. A distinguishing feature of the partners' Cornish business was the extent to which engines were moved. While engine moving was not unique to the Boulton and Watt engine (for it had been a regular occurrence with its Newcomen predecessors), in no other region were nearly as many of these engines moved. Out of the total of forty-nine recorded Boulton and Watt engines in Cornwall, only thirteen appear not to have been moved. Some engines were moved three times or more.
William Murdoch acted on Boulton and Watt's behalf in Cornwall and was clearly interested in locomotion. Nevetheless, it was the presence of so many Boulton and Watt engines, and the desire of the Cornish mine owners to get round paying royalties which provided the stimulus for Trevithick to develop strong steam and locomotion.
Watt died at Heathfield in Handsworth, Birmingham, on 25 August 1819 and was buried beside Matthew Boulton in St Mary's Church, Handsworth, on 2 September.
In 1824 Lord Liverpool initiated a public subscription for a memorial sculpture by Francis Chantrey in Westminster Abbey. It additionally had an inscription, written by Henry Brougham, which read: ''James Watt enlarged the resources of his country, increased the power of man and rose to an eminent place amongst the most illustrious followers of science and the real benefactors of the world.''
The Watt Institution and School of Arts in Edinburgh was in 1852 named after him; this was later amalgamated with the George Heriot Trust and subsequently became Heriot-Watt University. His life, as depicted by Samuel Smiles and later writers, became a paradigm of mechanical genius.
Cowper, Edward A. On the inventions of
James Watt, and his models preserved at Handsworth and South Kensington.
Proc. Instn Mech. Engrs.,
1883, 34, 599-631 + Plates 55-87.
Hills, R.L. The railways of James Watt. in Early railways: a selection of papers from the First International Railway Conferennce: edited by Andy Guy and Jim Rees. London: Newcomen Society. 2001.63-81.
Watt disliked locks as they limited capacity and favoured long level routes with wagonways at the end to accommodate the change in height: such canals were planned for Monkland, Strathmore and Campbeltown