James Watt

Scottish inventor, mechanical engineer, and chemist James Watt FRS FRSE Sadly died 25 August 1819 at his home “Heathfield” in Handsworth, Staffordshire (now part of Birmingham) at the age of 83. He was born 30 January 1736 (19 January 1736 OS in Greenock, Renfrewshire. His father was a shipwright, ship owner and contractor, and served as the town’s chief baillie,while his mother, Agnes Muirhead, came from a well educated distinguished family. Watt’s grandfather, Thomas Watt, was a mathematics teacher and baillie to the Baron of Cartsburn. Watt did not attend school regularly; initially he was mostly schooled at home by his mother but later he attended Greenock Grammar School. He exhibited great manual dexterity, engineering skills and an aptitude for mathematics, but is said to have suffered prolonged bouts of ill-health as a child.

When he was eighteen, his mother died and his father’s health began to fail. Watt travelled to London to study instrument-making for a year, then returned to Scotland, settling in Glasgow intent on setting up his own instrument-making business. He made and repaired brass reflecting quadrants, parallel rulers, scales, parts for telescopes, and barometers, among other things. However Because he had not served at least seven years as an apprentice, the Glasgow Guild of Hammermen (which had jurisdiction over any artisans using hammers) blocked his application, despite there being no other mathematical instrument makers in Scotland.

However the arrival of astronomical instruments, bequeathed by Alexander Macfarlane to the University of Glasgow which required expert handling, Allowed Watt to bypass this stalemate. These instruments were eventually installed in the Macfarlane Observatory. He was offered the opportunity to set up a small workshop within the university by two of the professors, the physicist and chemist Joseph Black and Adam Smith. At first he worked on maintaining and repairing scientific instruments used in the university, helping with demonstrations, and expanding the production of quadrants. 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 sixteen workers.

While working as an instrument maker at the University of Glasgow, Watt became interested in the technology of steam engines After noticing the steam from a boiling kettle forced the lid to move. His friend, John Robison, then suggested steam could be used as a source of motive power. He realized that contemporary steam engine designs wasted a great deal of energy by repeatedly cooling and reheating the cylinder. 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 dramatically improved on the efficiency of Thomas Newcomen’s 1712 Newcomen steam engine with his Watt steam engine in 1781, which was fundamental to the changes brought by the Industrial Revolution in both his native Great Britain and the rest of the world.

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. He realised the importance of latent heat—the thermal energy released or absorbed during a constant-temperature process—in understanding the engine, which, unknown to Watt, his friend Joseph Black had previously discovered some years before. 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 three-quarters of the thermal energy of the steam was being wasted heating the engine cylinder on every cycle.

Watt decided to condense the steam 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. Sadly Watt had financial difficulties constructing a full scale engine to demonstrate his findings. Luckily backing came from John Roebuck, the founder of the celebrated Carron Iron Works near Falkirk, 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, however the Piston and cylinder could not be manufactured with sufficient precision. Watt also worked first as a surveyor, then as a civil engineer for eight years to finance his work. Sadly

Sadly Roebuck went bankrupt, however salvation came in the form of Matthew Boulton, who owned the Soho Manufactory works near Birmingham, and acquired his patent rights. 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 making at Bersham, near Wrexham, North Wales. Watt and Boulton formed a hugely successful partnership (Boulton and Watt) which lasted for the next twenty-five years.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 to move the pump rods at the bottom of the shaft. The design was commercially successful, and for the next five years Watt installed more engines, mostly in Cornwall 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. 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 seemed the obvious solution to the conversion Watt and Boulton were stymied by a patent for this, whose holder, James Pickard, and associates proposed to cross-license the external condenser. Watt adamantly opposed this and they circumvented the patent by their sun and planet gear in 1781.

Watt made a number of other improvements and modifications to the steam engine. Such as A double acting engine, in which the steam acted alternately on the two sides of the piston. He also described methods for working the steam “expansively” (i.e., using steam at pressures well above atmospheric). He designed A compound engine, which connected two or more engines, a steam indicator which prevented these primative boilers from exploding and parallel motion 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. He also created a throttle valve to control the power of the engine, and a centrifugal governor, all of which made his Steam Engines far more efficient than the Newcomen Engine. In order to minimaze the risk of exploding boilers, Watt restricted his use of high pressure steam and all of his engines used steam at near atmospheric pressure. Watt entered a partnership with Matthew Boulton in 1775. The new firm of Boulton and Watt was eventually highly successful and Watt became a wealthy man.

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 and James Watt Jr. Watt continued to invent other things before and during his semi-retirement though none was as significant as his steam engine work. He invented and constructed several machines for copying sculptures and medallions. 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 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. In 1816 he took a trip on the paddle-steamer Comet, a product of his inventions, to revisit his home town of Greenock. 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. The availability of efficient, reliable motive power made whole new classes of industry economically viable, and altered the economies of continents. This brought about immense social change, attracting millions of rural families to the towns and cities.

Following his death He was buried on 2 September in the graveyard of St Mary’s Church, Handsworth. However he received many honours for his pioneering work during his lifetime. In 1784 he was made a fellow of the Royal Society of Edinburgh, and was elected as a member of the Batavian Society for Experimental Philosophy, of Rotterdam in 1787. In 1789 he was elected to the elite group, the Smeatonian Society of Civil Engineers. In 1806 he was conferred the honorary Doctor of Laws by the University of Glasgow. The French Academy elected him a Corresponding Member and he was made a Foreign Associate in 1814. The watt is named after James Watt for his contributions to the development of the steam engine, and was adopted by the Second Congress of the British Association for the Advancement of Science in 1889 and by the 11th General Conference on Weights and Measures in 1960 as the unit of power incorporated in the International System of Units (or “SI”).Boulton and Watt also feature on a Bank of England £50 note. the two industrialists pictured 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). In 2011 he was one of seven inaugural inductees to the Scottish Engineering Hall of Fame.

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