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James Watt (; 30 January 1736 (19 January 1736 OS) – 25 August 1819) was a Scottish
inventor An invention is a unique or novel device, method, composition, idea or process. An invention may be an improvement upon a machine, product, or process for increasing efficiency or lowering cost. It may also be an entirely new concept. If an i ...
,
mechanical engineer Mechanical may refer to: Machine * Machine (mechanical), a system of mechanisms that shape the actuator input to achieve a specific application of output forces and movement * Mechanical calculator, a device used to perform the basic operations ...
, and
chemist A chemist (from Greek ''chēm(ía)'' alchemy; replacing ''chymist'' from Medieval Latin ''alchemist'') is a scientist trained in the study of chemistry. Chemists study the composition of matter and its properties. Chemists carefully describe t ...
who improved on
Thomas Newcomen Thomas Newcomen (; February 1664 – 5 August 1729) was an English inventor who created the atmospheric engine, the first practical fuel-burning engine in 1712. He was an ironmonger by trade and a Baptist lay preacher by calling. He ...
's 1712 Newcomen steam engine with his
Watt steam engine The Watt steam engine design became synonymous with steam engines, and it was many years before significantly new designs began to replace the basic Watt design. The first steam engines, introduced by Thomas Newcomen in 1712, were of the "at ...
in 1776, which was fundamental to the changes brought by the
Industrial Revolution The Industrial Revolution was the transition to new manufacturing processes in Great Britain, continental Europe, and the United States, that occurred during the period from around 1760 to about 1820–1840. This transition included going f ...
in both his native Great Britain and the rest of the world. While working as an instrument maker at the University of Glasgow, Watt became interested in the technology of
steam engine A steam engine is a heat engine that performs mechanical work using steam as its working fluid. The steam engine uses the force produced by steam pressure to push a piston back and forth inside a cylinder. This pushing force can be tr ...
s. He realised that contemporary engine designs wasted a great deal of energy by repeatedly cooling and reheating the
cylinder A cylinder (from ) has traditionally been a three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a prism with a circle as its base. A cylinder may also be defined as an infi ...
. Watt introduced a design enhancement, the separate condenser, which avoided this waste of energy and radically improved the power, efficiency, and cost-effectiveness of steam engines. Eventually, he adapted his engine to produce rotary motion, greatly broadening its use beyond pumping water. Watt attempted to commercialise his invention, but experienced great financial difficulties until he entered a partnership with Matthew Boulton in 1775. The new firm of
Boulton and Watt Boulton & Watt was an early British engineering and manufacturing firm in the business of designing and making marine and stationary steam engines. Founded in the English West Midlands around Birmingham in 1775 as a partnership between the Engl ...
was eventually highly successful and Watt became a wealthy man. In his retirement, Watt continued to develop new inventions though none was as significant as his steam engine work. As Watt developed the concept of horsepower, the SI unit of power, the
watt The watt (symbol: W) is the unit of power or radiant flux in the International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantify the rate of energy transfer. The watt is named after James Wa ...
, was named after him.


Biography


Early life and education

James Watt was born on 19 January 1736 in
Greenock Greenock (; sco, Greenock; gd, Grianaig, ) is a town and administrative centre in the Inverclyde council area in Scotland, United Kingdom and a former burgh within the historic county of Renfrewshire, located in the west central Lowlands o ...
,
Renfrewshire Renfrewshire () ( sco, Renfrewshire; gd, Siorrachd Rinn Friù) is one of the 32 council areas of Scotland. Located in the west central Lowlands, it is one of three council areas contained within the boundaries of the historic county of Renf ...
, the eldest of the five surviving children of Agnes Muirhead (1703–1755) and James Watt (1698–1782). His mother came from a distinguished family, was well educated and said to be of forceful character, while his father was a shipwright, ship owner and contractor, and served as the Greenock's chief baillie in 1751. The Watt family's wealth came in part from Watt's father's trading in slaves and slave-produced goods. Watt's parents were
Presbyterian Presbyterianism is a part of the Reformed tradition within Protestantism that broke from the Roman Catholic Church in Scotland by John Knox, who was a priest at St. Giles Cathedral (Church of Scotland). Presbyterian churches derive their na ...
s and strong
Covenanters Covenanters ( gd, Cùmhnantaich) were members of a 17th-century Scottish religious and political movement, who supported a Presbyterian Church of Scotland, and the primacy of its leaders in religious affairs. The name is derived from '' Coven ...
, but despite his religious upbringing he later became a
deist Deism ( or ; derived from the Latin ''deus'', meaning "god") is the Philosophy, philosophical position and Rationalism, rationalistic theology that generally rejects revelation as a source of divine knowledge, and asserts that Empirical evi ...
. Watt's grandfather, Thomas Watt (1642–1734), was a teacher of mathematics, surveying and navigation and baillie to the Baron of Cartsburn. Initially, Watt was educated at home by his mother, later going on to attend Greenock Grammar School. There he exhibited an aptitude for mathematics, while
Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through ...
and
Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...
failed to interest him. Watt is said to have suffered prolonged bouts of ill-health as a child and from frequent headaches all his life. After leaving school, Watt worked in the workshops of his father's businesses, demonstrating considerable dexterity and skill in creating engineering models. After his father suffered unsuccessful business ventures, Watt left Greenock to seek employment in
Glasgow Glasgow ( ; sco, Glesca or ; gd, Glaschu ) is the most populous city in Scotland and the fourth-most populous city in the United Kingdom, as well as being the 27th largest city by population in Europe. In 2020, it had an estimated popul ...
as a mathematical instrument maker. When he was 18, Watt's mother died and his father's health began to fail. Watt travelled to
London London is the capital and List of urban areas in the United Kingdom, largest city of England and the United Kingdom, with a population of just under 9 million. It stands on the River Thames in south-east England at the head of a estuary dow ...
and was able to obtain a period of training as an instrument maker for a year (1755–56), then returned to Scotland, settling in the major commercial city of
Glasgow Glasgow ( ; sco, Glesca or ; gd, Glaschu ) is the most populous city in Scotland and the fourth-most populous city in the United Kingdom, as well as being the 27th largest city by population in Europe. In 2020, it had an estimated popul ...
, intent on setting up his own instrument-making business. He was still very young and, having not had a full
apprenticeship Apprenticeship is a system for training a new generation of practitioners of a trade or profession with on-the-job training and often some accompanying study (classroom work and reading). Apprenticeships can also enable practitioners to gain a ...
, did not have the usual connections via a former master to establish himself as a
journeyman A journeyman, journeywoman, or journeyperson is a worker, skilled in a given building trade or craft, who has successfully completed an official apprenticeship qualification. Journeymen are considered competent and authorized to work in that fie ...
instrument maker. Watt was saved from this impasse by the arrival from Jamaica of
astronomical instruments Astronomical instruments include: *Alidade *Armillary sphere * Astrarium *Astrolabe *Astronomical clock *the Antikythera mechanism, an astronomical clock *Blink comparator *Bolometer *the Canterbury Astrolabe Quadrant *Celatone *Celestial sphere * ...
bequeathed by
Alexander MacFarlane Alexander Macfarlane FRSE LLD (21 April 1851 – 28 August 1913) was a Scottish logician, physicist, and mathematician. Life Macfarlane was born in Blairgowrie, Scotland, to Daniel MacFarlane (Shoemaker, Blairgowire) and Ann Small. He s ...
to the University of Glasgow - instruments that required expert attention. Watt restored them to working order and was remunerated. These instruments were eventually installed in the Macfarlane Observatory. Subsequently, three professors offered him the opportunity to set up a small workshop within the university. It was initiated in 1757 and two of the professors, the
physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate caus ...
and
chemist A chemist (from Greek ''chēm(ía)'' alchemy; replacing ''chymist'' from Medieval Latin ''alchemist'') is a scientist trained in the study of chemistry. Chemists study the composition of matter and its properties. Chemists carefully describe t ...
Joseph Black as well as the famed economist
Adam Smith Adam Smith (baptized 1723 – 17 July 1790) was a Scottish economist and philosopher who was a pioneer in the thinking of political economy and key figure during the Scottish Enlightenment. Seen by some as "The Father of Economics"—— ...
, became Watt's friends. At first, he worked on maintaining and repairing scientific instruments used in the university, helping with demonstrations, and expanding the production of quadrants. He made and repaired brass reflecting quadrants, parallel rulers,
scales Scale or scales may refer to: Mathematics * Scale (descriptive set theory), an object defined on a set of points * Scale (ratio), the ratio of a linear dimension of a model to the corresponding dimension of the original * Scale factor, a number w ...
, parts for
telescope A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to observ ...
s, and
barometer A barometer is a scientific instrument that is used to measure air pressure in a certain environment. Pressure tendency can forecast short term changes in the weather. Many measurements of air pressure are used within surface weather analysis ...
s, among other things. It is sometimes falsely stated that he struggled to establish himself in Glasgow due to opposition from the Trades House, but this myth has been thoroughly debunked by the historian Harry Lumsden. The records from this period are lost, but it is known that he was able to work and trade completely normally as a skilled metal worker so the Incorporation of Hammermen must have been satisfied that he met their requirements for membership. It is also known that other people in the metal trades were pursued for working without being members of the Incorporation well into the 19th century, so the rules were definitely being enforced when Watt was trading freely throughout the city. In 1759, he formed a partnership with John Craig, an architect and businessman, to manufacture and sell a line of products including musical instruments and toys. This partnership lasted for the next six years, and employed up to 16 workers. Craig died in 1765. One employee, Alex Gardner, eventually took over the business, which lasted into the 20th century. In 1764, Watt married his cousin Margaret (Peggy) Miller, with whom he had 5 children, 2 of whom lived to adulthood: James Jr. (1769–1848) and Margaret (1767–1796). His wife died in childbirth in 1773. In 1777, he married again, to Ann MacGregor, daughter of a Glasgow dye-maker, with whom he had 2 children: Gregory (1777–1804), who became a geologist and mineralogist, and Janet (1779–1794). Ann died in 1832. Between 1777 and 1790 he lived in Regent Place,
Birmingham Birmingham ( ) is a City status in the United Kingdom, city and metropolitan borough in the metropolitan county of West Midlands (county), West Midlands in England. It is the second-largest city in the United Kingdom with a population of 1. ...
.


Watt and the kettle

There is a popular story that Watt was inspired to invent the steam engine by seeing a kettle boiling, the steam forcing the lid to rise and thus showing Watt the power of steam. This story is told in many forms; in some Watt is a young lad, in others he is older, sometimes it's his mother's kettle, sometimes his aunt's. Watt did not actually ''invent'' the steam engine, as the story implies, but dramatically improved the efficiency of the existing Newcomen engine by adding a separate condenser. This is difficult to explain to someone not familiar with concepts of heat and thermal efficiency. It appears that the story was created, possibly by Watt's son James Watt Jr., and persists because it is easy for children to understand and remember. In this light, it can be seen as akin to the story of Isaac Newton and the falling apple and his discovery of
gravity In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the str ...
. Although it is often dismissed as a myth, the story of Watt and the kettle has a basis in fact. In trying to understand the
thermodynamics Thermodynamics is a branch of physics that deals with heat, work, and temperature, and their relation to energy, entropy, and the physical properties of matter and radiation. The behavior of these quantities is governed by the four laws o ...
of heat and steam, James Watt carried out many laboratory experiments and his diaries record that in conducting these, he used a kettle as a boiler to generate steam.


Early experiments with steam

In 1759, Watt's friend, John Robison, called his attention to the use of steam as a source of motive power. The design of the Newcomen engine, in use for almost 50 years for pumping water from mines, had hardly changed from its first implementation. Watt began to experiment with steam, though he had never seen an operating steam engine. He tried constructing a model; it failed to work satisfactorily, but he continued his experiments and began to read everything he could about the subject. He came to realise the importance of
latent heat Latent heat (also known as latent energy or heat of transformation) is energy released or absorbed, by a body or a thermodynamic system, during a constant-temperature process — usually a first-order phase transition. Latent heat can be underst ...
—the
thermal energy The term "thermal energy" is used loosely in various contexts in physics and engineering. It can refer to several different well-defined physical concepts. These include the internal energy or enthalpy of a body of matter and radiation; heat, ...
released or absorbed during a constant-temperature process—in understanding the engine, which, unknown to Watt, his friend Joseph Black had previously discovered years before. Understanding of the steam engine was in a very primitive state, for the science of
thermodynamics Thermodynamics is a branch of physics that deals with heat, work, and temperature, and their relation to energy, entropy, and the physical properties of matter and radiation. The behavior of these quantities is governed by the four laws o ...
would not be formalised for nearly another 100 years. In 1763, Watt was asked to repair a model Newcomen engine belonging to the university. Even after repair, the engine barely worked. After much experimentation, Watt demonstrated that about 3/4 of the thermal energy of the steam was being consumed in heating the engine cylinder on every cycle. This energy was wasted because, later in the cycle, cold water was injected into the cylinder to
condense Condensation is the change of the state of matter from the gas phase into the liquid phase, and is the reverse of vaporization. The word most often refers to the water cycle. It can also be defined as the change in the state of water vapor to ...
the steam to reduce its pressure. Thus, by repeatedly heating and cooling the cylinder, the engine wasted most of its thermal energy rather than converting it into
mechanical energy In physical sciences, mechanical energy is the sum of potential energy and kinetic energy. The principle of conservation of mechanical energy states that if an isolated system is subject only to conservative forces, then the mechanical energy is ...
. Watt's critical insight, arrived at in May 1765 as he crossed Glasgow Green park, was to cause the steam to condense in a separate chamber apart from the piston, and to maintain the temperature of the cylinder at the same temperature as the injected steam by surrounding it with a "steam jacket". Thus, very little energy was absorbed by the cylinder on each cycle, making more available to perform useful work. Watt had a working model later that same year. Despite a potentially workable design, there were still substantial difficulties in constructing a full-scale engine. This required more
capital Capital may refer to: Common uses * Capital city, a municipality of primary status ** List of national capital cities * Capital letter, an upper-case letter Economics and social sciences * Capital (economics), the durable produced goods used fo ...
, some of which came from Black. More substantial backing came from
John Roebuck John Roebuck of Kinneil FRS FRSE (1718 – 17 July 1794) was an English inventor and industrialist who played an important role in the Industrial Revolution and who is known for developing the industrial-scale manufacture of sulphuric aci ...
, the founder of the celebrated Carron Iron Works near
Falkirk Falkirk ( gd, An Eaglais Bhreac, sco, Fawkirk) is a large town in the Central Lowlands of Scotland, historically within the county of Stirlingshire. It lies in the Forth Valley, northwest of Edinburgh and northeast of Glasgow. Falkirk had ...
, with whom he now formed a partnership. Roebuck lived at Kinneil House in Bo'ness, during which time Watt worked at perfecting his steam engine in a cottage adjacent to the house. The shell of the cottage, and a very large part of one of his projects, still exist to the rear. The principal difficulty was in machining the piston and cylinder.
Iron Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in fro ...
workers of the day were more like blacksmiths than modern
machinist A machinist is a tradesperson or trained professional who not only operates machine tools, but also has the knowledge of tooling and materials required to create set ups on machine tools such as milling machines, grinders, lathes, and drilling m ...
s, and were unable to produce the components with sufficient precision. Much capital was spent in pursuing a
patent A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an enabling disclosure of the invention."A p ...
on Watt's invention. Strapped for resources, Watt was forced to take up employment—first as a
surveyor Surveying or land surveying is the technique, profession, art, and science of determining the terrestrial two-dimensional or three-dimensional positions of points and the distances and angles between them. A land surveying professional is c ...
, then as a
civil engineer A civil engineer is a person who practices civil engineering – the application of planning, designing, constructing, maintaining, and operating infrastructure while protecting the public and environmental health, as well as improving existing ...
—for 8 years. Roebuck went
bankrupt Bankruptcy is a legal process through which people or other entities who cannot repay debts to creditors may seek relief from some or all of their debts. In most jurisdictions, bankruptcy is imposed by a court order, often initiated by the debtor ...
, and Matthew Boulton, who owned the Soho Manufactory works near
Birmingham Birmingham ( ) is a City status in the United Kingdom, city and metropolitan borough in the metropolitan county of West Midlands (county), West Midlands in England. It is the second-largest city in the United Kingdom with a population of 1. ...
, acquired his patent rights. An extension of the patent to 1800 was successfully obtained in 1775. Through Boulton, Watt finally had access to some of the best iron workers in the world. The difficulty of the manufacture of a large cylinder with a tightly fitting piston was solved by John Wilkinson, who had developed precision boring techniques for
cannon A cannon is a large- caliber gun classified as a type of artillery, which usually launches a projectile using explosive chemical propellant. Gunpowder ("black powder") was the primary propellant before the invention of smokeless powder du ...
making at Bersham, near
Wrexham Wrexham ( ; cy, Wrecsam; ) is a city and the administrative centre of Wrexham County Borough in Wales. It is located between the Welsh mountains and the lower Dee Valley, near the border with Cheshire in England. Historically in the county ...
,
North Wales , area_land_km2 = 6,172 , postal_code_type = Postcode , postal_code = LL, CH, SY , image_map1 = Wales North Wales locator map.svg , map_caption1 = Six principal areas of Wales commonl ...
. Watt and Boulton formed a hugely successful partnership,
Boulton and Watt Boulton & Watt was an early British engineering and manufacturing firm in the business of designing and making marine and stationary steam engines. Founded in the English West Midlands around Birmingham in 1775 as a partnership between the Engl ...
, which lasted for the next 25 years.


First engines

In 1776, the first engines were installed and working in commercial enterprises. These first engines were used to power pumps and produced only
reciprocating motion Reciprocating motion, also called reciprocation, is a repetitive up-and-down or back-and-forth linear motion. It is found in a wide range of mechanisms, including reciprocating engines and pumps. The two opposite motions that comprise a single ...
to move the pump rods at the bottom of the shaft. The design was commercially successful, and for the next 5 years, Watt was very busy installing more engines, mostly in
Cornwall Cornwall (; kw, Kernow ) is a historic county and ceremonial county in South West England. It is recognised as one of the Celtic nations, and is the homeland of the Cornish people. Cornwall is bordered to the north and west by the Atlantic ...
, for pumping water out of mines. These early engines were not manufactured by Boulton and Watt, but were made by others according to drawings made by Watt, who served in the role of
consulting engineer Engineers, as practitioners of engineering, are professionals who invent, design, analyze, build and test machines, complex systems, structures, gadgets and materials to fulfill functional objectives and requirements while considering the ...
. The erection of the engine and its shakedown was supervised by Watt, at first, and then by men in the firm's employ. These were large machines. The first, for example, had a cylinder with a diameter of 50 inches and an overall height of about 24 feet, and required the construction of a dedicated building to house it. Boulton and Watt charged an annual payment, equal to 1/3 of the value of the coal saved in comparison to a Newcomen engine performing the same work. The field of application for the invention was greatly widened when Boulton urged Watt to convert the reciprocating motion of the piston to produce rotational power for grinding, weaving and milling. Although a
crank Crank may refer to: Mechanisms * Crank (mechanism), in mechanical engineering, a bent portion of an axle or shaft, or an arm keyed at right angles to the end of a shaft, by which motion is imparted to or received from it * Crankset, the componen ...
seemed the obvious solution to the conversion, Watt and Boulton were stymied by a patent for this, whose holder, James Pickard and his associates proposed to cross-license the external condenser. Watt adamantly opposed this and they circumvented the patent by their
sun and planet gear The sun and planet gear is a method of converting reciprocating motion to rotary motion and was used in the first rotative beam engines. It was invented by the Scottish engineer William Murdoch, an employee of Boulton and Watt, but was patente ...
in 1781. Over the next 6 years, he made other improvements and modifications to the steam engine. A double-acting engine, in which the steam acted alternately on both sides of the piston, was one. He described methods for working the steam "expansively" (i.e., using steam at pressures well above atmospheric). A compound engine, which connected 2 or more engines, was described. Two more patents were granted for these in 1781 and 1782. Numerous other improvements that made for easier manufacture and installation were continually implemented. One of these included the use of the steam
indicator Indicator may refer to: Biology * Environmental indicator of environmental health (pressures, conditions and responses) * Ecological indicator of ecosystem health (ecological processes) * Health indicator, which is used to describe the health ...
which produced an informative plot of the pressure in the cylinder against its volume, which he kept as a
trade secret Trade secrets are a type of intellectual property that includes formulas, practices, processes, designs, instruments, patterns, or compilations of information that have inherent economic value because they are not generally known or readily as ...
. Another important invention, one which Watt was most proud of, was the parallel motion linkage, which was essential in double-acting engines as it produced the straight line motion required for the cylinder rod and pump, from the connected rocking beam, whose end moves in a circular arc. This was patented in 1784. A
throttle A throttle is the mechanism by which fluid flow is managed by constriction or obstruction. An engine's power can be increased or decreased by the restriction of inlet gases (by the use of a throttle), but usually decreased. The term ''throttle'' ...
valve to control the power of the engine, and a
centrifugal governor A centrifugal governor is a specific type of governor with a feedback system that controls the speed of an engine by regulating the flow of fuel or working fluid, so as to maintain a near-constant speed. It uses the principle of proportional cont ...
, patented in 1788, to keep it from "running away" were very important. These improvements taken together produced an engine which was up to 5 times as fuel efficient as the Newcomen engine. Because of the danger of exploding boilers, which were in a very primitive stage of development, and the ongoing issues with leaks, Watt restricted his use of high pressure steam – all of his engines used steam at near atmospheric pressure.


Patent trials

Edward Bull started constructing engines for Boulton and Watt in Cornwall in 1781. By 1792, he had started making engines of his own design, but which contained a separate condenser, and so infringed Watt's patents. Two brothers, Jabez Carter Hornblower and
Jonathan Hornblower Jonathan Hornblower (5 July 1753 – 23 February 1815) was an English pioneer of steam power. Personal life The son of Jonathan Hornblower the Elder and the brother of Jabez Carter Hornblower, two fellow pioneers, the young Hornblower wa ...
Jnr also started to build engines about the same time. Others began to modify Newcomen engines by adding a condenser, and the mine owners in Cornwall became convinced that Watt's patent could not be enforced. They started to withhold payments to Boulton and Watt, which by 1795 had fallen on hard times. Of the total £21,000 (equivalent to £ as of ) owed, only £2,500 had been received. Watt was forced to go to court to enforce his claims. He first sued Bull in 1793. The jury found for Watt, but the question of whether or not the original specification of the patent was valid was left to another trial. In the meantime, injunctions were issued against the infringers, forcing their payments of the
royalties A royalty payment is a payment made by one party to another that owns a particular asset, for the right to ongoing use of that asset. Royalties are typically agreed upon as a percentage of gross or net revenues derived from the use of an asset o ...
to be placed in
escrow An escrow is a contractual arrangement in which a third party (the stakeholder or escrow agent) receives and disburses money or property for the primary transacting parties, with the disbursement dependent on conditions agreed to by the transacti ...
. The trial on determining the validity of the specifications which was held in the following year was inconclusive, but the injunctions remained in force and the infringers, except for Jonathan Hornblower, all began to settle their cases. Hornblower was soon brought to trial in 1799, and the verdict of the four was decisively in favour of Watt. Their friend John Wilkinson, who had solved the problem of boring an accurate cylinder, was a particularly grievous case. He had erected about 20 engines without Boulton's and Watts' knowledge. They finally agreed to settle the infringement in 1796. Boulton and Watt never collected all that was owed them, but the disputes were all settled directly between the parties or through arbitration. These trials were extremely costly in both money and time, but ultimately were successful for the firm.


Copying machine

Before 1780, there was no good method for making copies of letters or drawings. The only method sometimes used was a mechanical one using multiple linked pens. Watt at first experimented with improving this method, but soon gave up on this approach because it was so cumbersome. He instead decided to try to physically transfer ink from the front of the original to the back of another sheet, moistened with a solvent, and pressed to the original. The second sheet had to be thin, so that the ink could be seen through it when the copy was held up to the light, thus reproducing the original exactly. Watt started to develop the process in 1779, and made many experiments to formulate the ink, select the thin paper, to devise a method for wetting the special thin paper, and to make a press suitable for applying the correct pressure to effect the transfer. All of these required much experimentation, but he soon had enough success to patent the process a year later. Watt formed another partnership with Boulton (who provided financing) and
James Keir James Keir FRS (20 September 1735 – 11 October 1820) was a Scottish chemist, geologist, industrialist, and inventor, and an important member of the Lunar Society of Birmingham. Life and work Keir was born in Stirlingshire, Scotland, in 1 ...
(to manage the business) in a firm called James Watt and Co. The perfection of the invention required much more development work before it could be routinely used by others, but this was carried out over the next few years. Boulton and Watt gave up their shares to their sons in 1794. It became a commercial success and was widely used in offices even into the 20th century.


Chemical experiments

From an early age, Watt was very interested in chemistry. In late 1786, while in Paris, he witnessed an experiment by Claude Louis Berthollet in which he reacted
hydrochloric acid Hydrochloric acid, also known as muriatic acid, is an aqueous solution of hydrogen chloride. It is a colorless solution with a distinctive pungent smell. It is classified as a strong acid. It is a component of the gastric acid in the digesti ...
with
manganese dioxide Manganese dioxide is the inorganic compound with the formula . This blackish or brown solid occurs naturally as the mineral pyrolusite, which is the main ore of manganese and a component of manganese nodules. The principal use for is for dry-cel ...
to produce
chlorine Chlorine is a chemical element with the symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine ...
. He had already found that an
aqueous solution An aqueous solution is a solution in which the solvent is water. It is mostly shown in chemical equations by appending (aq) to the relevant chemical formula. For example, a solution of table salt, or sodium chloride (NaCl), in water would be ...
of chlorine could bleach textiles, and had published his findings, which aroused great interest among many potential rivals. When Watt returned to Britain, he began experiments along these lines with hopes of finding a commercially viable process. He discovered that a mixture of salt, manganese dioxide and
sulphuric acid Sulfuric acid ( American spelling and the preferred IUPAC name) or sulphuric acid ( Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen and hydrogen, with the molecular ...
could produce chlorine, which Watt believed might be a cheaper method. He passed the chlorine into a weak solution of
alkali In chemistry, an alkali (; from ar, القلوي, al-qaly, lit=ashes of the saltwort) is a basic, ionic salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as a base that dissolves in water. A solution of a s ...
, and obtained a
turbid Turbidity is the cloudiness or haziness of a fluid caused by large numbers of individual particles that are generally invisible to the naked eye, similar to smoke in air. The measurement of turbidity is a key test of water quality. Fluids can ...
solution that appeared to have good bleaching properties. He soon communicated these results to James McGrigor, his father-in-law, who was a bleacher in Glasgow. Otherwise, he tried to keep his method a secret. With McGrigor and his wife Annie, he started to scale up the process, and in March 1788, McGrigor was able to bleach of cloth to his satisfaction. About this time, Berthollet discovered the salt and sulphuric acid process, and published it, so it became public knowledge. Many others began to experiment with improving the process, which still had many shortcomings, not the least of which was the problem of transporting the liquid product. Watt's rivals soon overtook him in developing the process, and he dropped out of the race. It was not until 1799, when
Charles Tennant Charles Tennant (3 May 1768 – 1 October 1838) was a Scottish chemist and industrialist. He discovered Calcium hypochlorite, bleaching powder and founded an industrial dynasty. Biography Charles Tennant was born at Laigh Corton, Alloway, Ayrs ...
patented a process for producing solid bleaching powder (
calcium hypochlorite Calcium hypochlorite is an inorganic compound with formula Ca(OCl)2. It is the main active ingredient of commercial products called bleaching powder, chlorine powder, or chlorinated lime, used for water treatment and as a bleaching agent. Thi ...
) that it became a commercial success. By 1794, Watt had been chosen by Thomas Beddoes to manufacture apparatuses to produce, clean and store gases for use in the new
Pneumatic Institution The Pneumatic Institution (also referred to as Pneumatic Institute) was a medical research facility in Bristol, England, in 1799–1802. It was established by physician and science writer Thomas Beddoes to study the medical effects of gases, kno ...
at Hotwells in
Bristol Bristol () is a city, ceremonial county and unitary authority in England. Situated on the River Avon, it is bordered by the ceremonial counties of Gloucestershire to the north and Somerset to the south. Bristol is the most populous city in ...
. Watt continued to experiment with various gases, but by 1797, the medical uses for the "
factitious airs Factitious airs was a term used for synthetic gases which emerged around 1670 when Robert Boyle coined the term upon isolating what is now understood to be hydrogen. ''Factitious'' means "artificial, not natural", so the term means "man-made gases ...
" (artificial gases) had come to a dead end.


Personality

Watt combined theoretical knowledge of science with the ability to apply it practically. Chemist Humphry Davy said of him, "Those who consider James Watt only as a great practical mechanic form a very erroneous idea of his character; he was equally distinguished as a
natural philosopher Natural philosophy or philosophy of nature (from Latin ''philosophia naturalis'') is the philosophical study of physics, that is, nature and the physical universe. It was dominant before the development of modern science. From the ancient ...
and a chemist, and his inventions demonstrate his profound knowledge of those sciences, and that peculiar characteristic of genius, the union of them for practical application". He was greatly respected by other prominent men of the
Industrial Revolution The Industrial Revolution was the transition to new manufacturing processes in Great Britain, continental Europe, and the United States, that occurred during the period from around 1760 to about 1820–1840. This transition included going f ...
. He was an important member of the Lunar Society of Birmingham, and was a much sought-after conversationalist and companion, always interested in expanding his horizons. His personal relationships with his friends and business partners were always congenial and long-lasting. According to Lord Liverpool (Prime Minister of the UK),
A more excllent and amikable man in all the relations of life I believe never existed.
Watt was a prolific correspondent. During his years in
Cornwall Cornwall (; kw, Kernow ) is a historic county and ceremonial county in South West England. It is recognised as one of the Celtic nations, and is the homeland of the Cornish people. Cornwall is bordered to the north and west by the Atlantic ...
, he wrote long letters to Boulton several times per week. He was averse to publishing his results in, for example, the '' Philosophical Transactions of the Royal Society'' however, and instead preferred to communicate his ideas in patents. He was an excellent draughtsman. He was a rather poor businessman, and especially hated bargaining and negotiating terms with those who sought to use the steam engine. In a letter to William Small in 1772, Watt confessed that "he would rather face a loaded cannon than settle an account or make a bargain." Until he retired, he was always very concerned about his financial affairs, and was something of a worrier. His health was often poor and he suffered frequent nervous headaches and depression. When he retired in 1800, he became a rich enough man to pass the business on to his sons.


Soho Foundry

At first, the partnership made the drawings and specifications for the engines, and supervised the work to erect them on the customers' property. They produced almost none of the parts themselves. Watt did most of his work at his home in Harper's Hill in Birmingham, while Boulton worked at the Soho Manufactory. Gradually, the partners began to actually manufacture more and more of the parts, and by 1795, they purchased a property about a mile away from the Soho Manufactory, on the banks of the Birmingham Canal, to establish a new foundry for the manufacture of the engines. The
Soho Foundry Soho Foundry is a factory created in 1775 by Matthew Boulton and James Watt and their sons Matthew Robinson Boulton and James Watt Jr. at Smethwick, West Midlands, England (), for the manufacture of steam engines. Now owned by Avery Weigh- ...
formally opened in 1796 at a time when Watt's sons, Gregory and James Jr. were heavily involved in the management of the enterprise. In 1800, the year of Watt's retirement, the firm made a total of 41 engines.


Later years

Watt retired in 1800, the same year that his fundamental patent and partnership with Boulton expired. The famous partnership was transferred to the men's sons,
Matthew Robinson Boulton Matthew Robinson Boulton (8 August 1770 – 16 May 1842) was an English manufacturer, a pioneer of management, the son of Matthew Boulton and the father of Matthew Piers Watt Boulton, who first patented the aileron. He was responsible with Jam ...
and James Watt Jr.. Longtime firm engineer
William Murdoch William Murdoch (sometimes spelled Murdock) (21 August 1754 – 15 November 1839) was a Scottish engineer and inventor. Murdoch was employed by the firm of Boulton & Watt and worked for them in Cornwall, as a steam engine erector for ten ye ...
was soon made a partner and the firm prospered. Watt continued to invent other things before and during his semi-retirement. Within his home in Handsworth, Staffordshire, Watt made use of a garret room as a workshop, and it was here that he worked on many of his inventions. Among other things, he invented and constructed machines for copying sculptures and medallions which worked very well, but which he never patented. One of the first sculptures he produced with the machine was a small
head A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth, each of which aid in various sensory functions such as sight, hearing, smell, and taste. Some very simple animals may not ...
of his old professor friend
Adam Smith Adam Smith (baptized 1723 – 17 July 1790) was a Scottish economist and philosopher who was a pioneer in the thinking of political economy and key figure during the Scottish Enlightenment. Seen by some as "The Father of Economics"—— ...
. He maintained his interest in civil engineering and was a consultant on several significant projects. He proposed, for example, a method for constructing a flexible pipe to be used for pumping water under the River Clyde at Glasgow. He and his second wife travelled to France and Germany, and he purchased an estate in mid-Wales at Doldowlod House, one mile south of Llanwrthwl, which he much improved. In 1816, he took a trip on the paddle-steamer ''
Comet A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process that is called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail. These phenomena ...
'', a product of his inventions, to revisit his home town of Greenock. He died on 25 August 1819 at his home "
Heathfield Hall Heathfield Hall (sometimes referred to as Heathfield House) was a house in Handsworth, Staffordshire (the area became part of Birmingham in 1911), England, built for the engineer James Watt. In 1790, Watt's business partner Matthew Boulton re ...
" near Handsworth in Staffordshire (now part of Birmingham) at the age of 83. He was buried on 2 September in the graveyard of St Mary's Church, Handsworth. The church has since been extended and his grave is now inside the church.


Family

On 16 July 1764, Watt married his cousin Margaret Miller (d. 1773). They had two children, Margaret (1767–1796) and James (1769–1848). In 1791, their daughter married James Miller. In September 1773, while Watt was working in the
Scottish Highlands The Highlands ( sco, the Hielands; gd, a’ Ghàidhealtachd , 'the place of the Gaels') is a historical region of Scotland. Culturally, the Highlands and the Lowlands diverged from the Late Middle Ages into the modern period, when Lowland ...
, he learned that his wife, who was pregnant with their third child, was seriously ill. He immediately returned home but found that she had died and their child was
stillborn Stillbirth is typically defined as fetal death at or after 20 or 28 weeks of pregnancy, depending on the source. It results in a baby born without signs of life. A stillbirth can result in the feeling of guilt or grief in the mother. The term ...
. In 1775, he married Ann MacGregor (d.1832).


Freemasonry

He was Initiated into Scottish Freemasonry in The Glasgow Royal Arch Lodge, No. 77, in 1763. The Lodge ceased to exist in 1810. A
Masonic Lodge A Masonic lodge, often termed a private lodge or constituent lodge, is the basic organisational unit of Freemasonry. It is also commonly used as a term for a building in which such a unit meets. Every new lodge must be warranted or chartered ...
was named after him in his home town of Glasgow – Lodge James Watt, No. 1215.


Murdoch's contributions

William Murdoch joined Boulton and Watt in 1777. At first, he worked in the
pattern A pattern is a regularity in the world, in human-made design, or in abstract ideas. As such, the elements of a pattern repeat in a predictable manner. A geometric pattern is a kind of pattern formed of geometric shapes and typically repeated l ...
shop in Soho, but soon he was erecting engines in Cornwall. He became an important part of the firm and made many contributions to its success including important inventions of his own. John Griffiths, who wrote a biography of him in 1992, has argued that Watt's discouragement of Murdoch's work with high-pressure steam on his steam road locomotive experiments delayed its development: Watt rightly believed that boilers of the time would be unsafe at higher pressures. Watt patented the application of the
sun and planet gear The sun and planet gear is a method of converting reciprocating motion to rotary motion and was used in the first rotative beam engines. It was invented by the Scottish engineer William Murdoch, an employee of Boulton and Watt, but was patente ...
to steam in 1781 and a
steam locomotive A steam locomotive is a locomotive that provides the force to move itself and other vehicles by means of the expansion of steam. It is fuelled by burning combustible material (usually coal, oil or, rarely, wood) to heat water in the locomo ...
in 1784, both of which have strong claims to have been invented by Murdoch. The patent was never contested by Murdoch, however, and Boulton and Watt's firm continued to use the sun and planet gear in their rotative engines, even long after the patent for the crank expired in 1794. Murdoch was made a partner of the firm in 1810, where he remained until his retirement 20 years later at the age of 76.


Legacy

As one author states, James Watt's improvements to the steam engine "converted it from a prime mover of marginal efficiency into the mechanical workhorse of the Industrial Revolution".


Honours

Watt was much honoured in his own time. In 1784, he was made a fellow of the
Royal Society of Edinburgh The Royal Society of Edinburgh is Scotland's national academy of science and letters. It is a registered charity that operates on a wholly independent and non-partisan basis and provides public benefit throughout Scotland. It was established i ...
, and was elected as a member of the Batavian Society for Experimental Philosophy, of
Rotterdam Rotterdam ( , , , lit. ''The Dam on the River Rotte'') is the second largest city and municipality in the Netherlands. It is in the province of South Holland, part of the North Sea mouth of the Rhine–Meuse–Scheldt delta, via the ''"N ...
, the Netherlands, in 1787. In 1789, he was elected to the elite group, the
Smeatonian Society of Civil Engineers The Smeatonian Society of Civil Engineers was founded in England in 1771. It was the first engineering society to be formed anywhere in the world, and remains the oldest. It was originally known as the Society of Civil Engineers, being renamed fo ...
. In 1806, he was conferred the honorary
Doctor of Law A Doctor of Law is a degree in law. The application of the term varies from country to country and includes degrees such as the Doctor of Juridical Science (J.S.D. or S.J.D), Juris Doctor (J.D.), Doctor of Philosophy (Ph.D.), and Legum Doctor ( ...
s by the University of Glasgow. The
French Academy French (french: français(e), link=no) may refer to: * Something of, from, or related to France ** French language, which originated in France, and its various dialects and accents ** French people, a nation and ethnic group identified with Franc ...
elected him a Corresponding Member and he was made a Foreign Associate in 1814. The
watt The watt (symbol: W) is the unit of power or radiant flux in the International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantify the rate of energy transfer. The watt is named after James Wa ...
is named after James Watt for his contributions to the development of the
steam engine A steam engine is a heat engine that performs mechanical work using steam as its working fluid. The steam engine uses the force produced by steam pressure to push a piston back and forth inside a cylinder. This pushing force can be tr ...
, and was adopted by the Second Congress of the
British Association for the Advancement of Science The British Science Association (BSA) is a charity and learned society founded in 1831 to aid in the promotion and development of science. Until 2009 it was known as the British Association for the Advancement of Science (BA). The current Chie ...
in 1889 and by the 11th
General Conference on Weights and Measures The General Conference on Weights and Measures (GCWM; french: Conférence générale des poids et mesures, CGPM) is the supreme authority of the International Bureau of Weights and Measures (BIPM), the intergovernmental organization established i ...
in 1960 as the unit of power incorporated in the
International System of Units The International System of Units, known by the international abbreviation SI in all languages and sometimes Pleonasm#Acronyms and initialisms, pleonastically as the SI system, is the modern form of the metric system and the world's most wid ...
(or "SI"). On 29 May 2009, the
Bank of England The Bank of England is the central bank of the United Kingdom and the model on which most modern central banks have been based. Established in 1694 to act as the English Government's banker, and still one of the bankers for the Government of ...
announced that Boulton and Watt would appear on a new £50 note. The design is the first to feature a dual portrait on a Bank of England note, and presents the two industrialists side by side with images of Watt's steam engine and Boulton's Soho Manufactory. Quotes attributed to each of the men are inscribed on the note: "I sell here, sir, what all the world desires to have—POWER" (Boulton) and "I can think of nothing else but this machine" (Watt). The inclusion of Watt is the second time that a Scot has featured on a Bank of England note (the first was
Adam Smith Adam Smith (baptized 1723 – 17 July 1790) was a Scottish economist and philosopher who was a pioneer in the thinking of political economy and key figure during the Scottish Enlightenment. Seen by some as "The Father of Economics"—— ...
on the 2007 issue £20 note). In September 2011, it was announced that the notes would enter circulation on 2 November. In 2011, he was one of seven inaugural inductees to the
Scottish Engineering Hall of Fame The Scottish Engineering Hall of Fame honours "those engineers from, or closely associated with, Scotland who have achieved, or deserve to achieve, greatness", as selected by an independent panel representing Scottish engineering institutions, aca ...
.


Memorials

Watt was buried in the grounds of St. Mary's Church, Handsworth, in Birmingham. Later expansion of the church, over his grave, means that his tomb is now buried ''inside'' the church. The garret room workshop that Watt used in his retirement was left, locked and untouched, until 1853, when it was first viewed by his biographer J. P. Muirhead. Thereafter, it was occasionally visited, but left untouched, as a kind of shrine. A proposal to have it transferred to the Patent Office came to nothing. When the house was due to be demolished in 1924, the room and all its contents were presented to the
Science Museum A science museum is a museum devoted primarily to science. Older science museums tended to concentrate on static displays of objects related to natural history, paleontology, geology, industry and industrial machinery, etc. Modern trends in ...
, where it was recreated in its entirety. It remained on display for visitors for many years, but was walled-off when the gallery it was housed in closed. The workshop remained intact, and preserved, and in March 2011 was put on public display as part of a new permanent Science Museum exhibition, "James Watt and our world". The approximate location of James Watt's birth in Greenock is commemorated by a statue. Other memorials in Greenock include street names and the Watt Memorial Library, which was begun in 1816 with Watt's donation of scientific books, and developed as part of the Watt Institution by his son (which ultimately became the James Watt College). Taken over by the local authority in 1974, the library now also houses the local history collection and archives of
Inverclyde Inverclyde ( sco, Inerclyde, gd, Inbhir Chluaidh, , "mouth of the Clyde") is one of 32 council areas used for local government in Scotland. Together with the East Renfrewshire and Renfrewshire council areas, Inverclyde forms part of the histo ...
, and is dominated by a large seated statue in the vestibule. Watt is additionally commemorated by statuary in George Square, Glasgow and Princes Street, Edinburgh, as well as others in
Birmingham Birmingham ( ) is a City status in the United Kingdom, city and metropolitan borough in the metropolitan county of West Midlands (county), West Midlands in England. It is the second-largest city in the United Kingdom with a population of 1. ...
, where he is also remembered by the Moonstones and a school is named in his honour. The James Watt College has expanded from its original location to include campuses in Kilwinning (North Ayrshire), Finnart Street and The Waterfront in Greenock, and the Sports campus in
Largs Largs ( gd, An Leargaidh Ghallda) is a town on the Firth of Clyde in North Ayrshire, Scotland, about from Glasgow. The original name means "the slopes" (''An Leargaidh'') in Scottish Gaelic. A popular seaside resort with a pier, the town mark ...
. Heriot-Watt University near
Edinburgh Edinburgh ( ; gd, Dùn Èideann ) is the capital city of Scotland and one of its 32 council areas. Historically part of the county of Midlothian (interchangeably Edinburghshire before 1921), it is located in Lothian on the southern shore o ...
was at one time the School of Arts of Edinburgh, founded in 1821 as the world's first Mechanics Institute, but to commemorate George Heriot, the 16th-century financier to
King James VI and I James VI and I (James Charles Stuart; 19 June 1566 – 27 March 1625) was King of Scotland as James VI from 24 July 1567 and King of England and Ireland as James I from the union of the Scottish and English crowns on 24 March 1603 until hi ...
, and James Watt, after
Royal Charter A royal charter is a formal grant issued by a monarch under royal prerogative as letters patent. Historically, they have been used to promulgate public laws, the most famous example being the English Magna Carta (great charter) of 1215, b ...
the name was changed to Heriot-Watt University. Dozens of university and college buildings (chiefly of science and technology) are named after him. Matthew Boulton's home, Soho House, is now a museum, commemorating the work of both men. The University of Glasgow's Faculty of Engineering has its headquarters in the James Watt Building, which also houses the department of Mechanical Engineering and the department of Aerospace Engineering. The huge painting ''James Watt contemplating the steam engine'' by James Eckford Lauder is now owned by the National Gallery of Scotland. There is a statue of James Watt in Piccadilly Gardens, Manchester and City Square, Leeds. A colossal statue of Watt by Francis Legatt Chantrey was placed in
Westminster Abbey Westminster Abbey, formally titled the Collegiate Church of Saint Peter at Westminster, is an historic, mainly Gothic church in the City of Westminster, London, England, just to the west of the Palace of Westminster. It is one of the Unite ...
, and later was moved to
St. Paul's Cathedral St Paul's Cathedral is an Anglican cathedral in London and is the seat of the Bishop of London. The cathedral serves as the mother church of the Diocese of London. It is on Ludgate Hill at the highest point of the City of London and is a Grad ...
. On the cenotaph, the inscription reads, in part, "JAMES WATT ... ENLARGED THE RESOURCES OF HIS COUNTRY, INCREASED THE POWER OF MAN, AND ROSE TO AN EMINENT PLACE AMONG THE MOST ILLUSTRIOUS FOLLOWERS OF SCIENCE AND THE REAL BENEFACTORS OF THE WORLD". A bust of Watt is in the Hall of Heroes of the
National Wallace Monument The National Wallace Monument (generally known as the Wallace Monument) is a 67 metre tower on the shoulder of the Abbey Craig, a hilltop overlooking Stirling in Scotland. It commemorates Sir William Wallace, a 13th- and 14th-century Scottish her ...
in Stirling, Scotland.


Patents

Watt was the sole inventor listed on his 6 patents:Hills, vol 3, p. 13 * Patent 913: A method of lessening the consumption of steam in steam engines – the separate condenser. The specification was accepted on 5 January 1769; enrolled on 29 April 1769, and extended to June 1800 by an Act of Parliament in 1775. * Patent 1,244: A new method of copying letters. The specification was accepted on 14 February 1780 and enrolled on 31 May 1780. * Patent 1,306: New methods to produce a continued rotation motion – sun and planet. The specification was accepted on 25 October 1781 and enrolled on 23 February 1782. * Patent 1,321: New improvements upon steam engines – expansive and double acting. The specification was accepted on 14 March 1782 and enrolled on 4 July 1782. * Patent 1,432: New improvements upon steam engines – three bar motion and steam carriage. The specification was accepted on 28 April 1782 and enrolled on 25 August 1782. * Patent 1,485: Newly improved methods of constructing furnaces. The specification was accepted on 14 June 1785 and enrolled on 9 July 1785.


References


Sources

* "Some Unpublished Letters of James Watt" in ''Journal of
Institution of Mechanical Engineers The Institution of Mechanical Engineers (IMechE) is an independent professional association and learned society headquartered in London, United Kingdom, that represents mechanical engineers and the engineering profession. With over 120,000 membe ...
'' (London, 1915). * Carnegie, Andrew, ''James Watt'' University Press of the Pacific (2001) (Reprinted from the 1913 ed.), . * * Dickinson, H. W. and Hugh Pembroke Vowles ''James Watt and the Industrial Revolution'' (published in 1943, new edition 1948 and reprinted in 1949. Also published in Spanish and Portuguese (1944) by the British Council) * Hills, Rev. Dr. Richard L., ''James Watt, Vol 1, His time in Scotland, 1736–1774'' (2002); Vol 2, ''The years of toil, 1775–1785''; Vol 3 ''Triumph through adversity 1785–1819.'' Landmark Publishing Ltd, . * * * Marsden, Ben. ''Watt's Perfect Engine'' Columbia University Press (New York, 2002) . * Marshall, Thomas H. (1925), ''James Watt''
Chapter 3: Mathematical Instrument Maker
fro
Steam Engine Library
of University of Rochester Department of History. * Marshall, Thomas H. (1925
''James Watt''
University of Rochester Department of History. * * * Roll, Erich (1930). ''An Early Experiment in Industrial Organisation : being a History of the Firm of Boulton & Watt.'' 1775–1805. Longmans, Green and Co. * Smiles, Samuel, ''Lives of the Engineers'', (London, 1861–62, new edition, five volumes, 1905). ;Related topics * *


External links


James Watt by Andrew Carnegie (1905)

Librivox audiobook: James Watt by Andrew Carnegie (1905)

James Watt by Thomas H. Marshall (1925)

Archives of Soho
at Birmingham Central Library.
BBC History: James Watt



Revolutionary Players website

Cornwall Record Office Boulton and Watt letters


* {{DEFAULTSORT:Watt, James Scottish inventors 1736 births 1819 deaths Alumni of the University of Glasgow Fellows of the Royal Society Fellows of the Royal Society of Edinburgh Industrial Revolution in England Industrial Revolution in Scotland Members of the Lunar Society of Birmingham People associated with Heriot-Watt University People from Greenock People of the Scottish Enlightenment People associated with energy Scottish business theorists Scottish businesspeople Scottish chemists Scottish deists Scottish Presbyterians Scottish surveyors 18th-century British engineers 18th-century British scientists 18th-century Scottish people Scottish Engineering Hall of Fame inductees