James Watt

Categories: 1736 births | 1819 deaths | Business theorists | Fellows of the Royal Society | Lunar Society | Natives of Inverclyde | Scottish engineers | Scottish inventors | Scottish mathematicians | University of Glasgow alumni

This article is about the Scottish engineer and inventor. For Ronald Reagan's Secretary of the Interior, see James G. Watt. For the BBC Radio York presenter, see James Watt.

Image:James Watt small.jpg
James Watt

James Watt (January 19, 1736–August 19, 1819) was a Scottish mathematician and engineer whose improvements to the steam engine contributed to a key stage in the Industrial Revolution.

He was born in Greenock, Scotland; became an instrument maker to the University of Glasgow; then moved to Birmingham, England where he was a key member of the Lunar Society. Many of his papers are in Birmingham Central Library.

Contents

[edit]

Timeline

[edit]

Engineering Achievements

Watt adapted the centrifugal governor to regulate the speed of a steam engine. (This was already in use for governing wind and watermills.) He invented the parallel motion linkage to convert circular motion to an approximate straight line motion (of which he was most proud) and the steam indicator diagram to measure steam pressure in the cylinder throughout the working cycle of the engine, so showing its efficiency.

Watt greatly helped the development of the embryonic steam engine into a viable and economic means of power generation. He realised that the Newcomen steam engine was wasting nearly three quarters of the steam energy in heating the piston and chamber. Watt developed a separate condenser chamber which significantly increased the efficiency. Further refinements (insulation of the steam cylinder, the double-acting engine, a counter, an indicator, and a throttle valve) made the steam engine his life's work.

Watt was opposed to the use of high pressure steam, and is held by some to have held back the technical development of the steam engine by other engineers, until his patents expired in 1800. In particular his prohibitions on his employee William Murdoch working with high pressure steam on his steam locomotive experiments delayed the development & application of this invention. With his partner Matthew Boulton he battled against rival engineers such as Jonathan Hornblower who tried to develop engines which did not fall foul of his 'catch-all' patents. Boulton proved an excellent businessman, and both men eventually made fortunes.

He introduced a unit called the horsepower to compare the power output of steam engines, his version of the unit being equivalent to 550 foot-pounds per second (about 745.7 watts).

Watt also invented several other things, not least a copying device for letters.

[edit]

Controversy

There is some dispute as to whether Watt was the original inventor of some of the numerous inventions and principles which he filed patents for. It was his practice, (from around the 1780's) to file either vague patents or to pre-empt others ideas which were known to him by filing patents with the intention of securing credit for the invention for himself, and ensuring that no one else was able to carry out work in a particular field. As he states in a letter to Boulton of 17 August 1784:

"I have given such descriptions of engines for wheel carriages as I could do in the time and space I could allow myself; but it is very defective and can only serve to keep other people from similar patents".

Two examples of this practice are his patenting of the sun and planet gear in 1781 and a steam locomotive in 1784, both of which were originated and invented by his employee William Murdoch.

[edit]

Legacy

James Watt's model of the steam engine converted a machine of limited use to one of efficiency and multiple applications. It was the foremost energy source in the emerging Industrial Revolution, and greatly multiplied its productive capacity. (Without it, humans might have continued to provide power.) It was also essential in later transportation advances, such as the steamboat and locomotive.

Watt was ranked #22 on Michael H. Hart's list of the most influential figures in history.

Image:James Watt - Statue - Birmingham - 2005-10-13.jpg
Watt celebrated as a statue in central Birmingham
[edit]

Remembrance

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 SI unit of power, the watt, is named after him. So is, at least in part, Edinburgh's Heriot-Watt University.

He is also remembered by the Moonstones, two individual statues, and a statue of him, Boulton and Murdoch by William Bloye, and a school named in his honour, all in Birmingham.

There are 4 colleges named after him in Scotland, James Watt College in Kilwinning (North Ayrshire Campus) and Greenock (2 in Greenock, Finnart Campus and Waterfront Campus) and a campus in Largs.

Matthew Boulton's home, Soho House, is now a museum, commemorating the work of both men.

There are over 50 roads or streets named after him, in the UK.

[edit]

See also

and steam power predecessors:

[edit]

Bibliography

Rev. Dr. Richard L, Hills, James Watt, Vol 1, His time in Scotland, 1736-1774 (2002), 480pp, many illus., Landmark Publishing Ltd, (ISBN 1-84306-045-0) [The second volume covering his time in England until his death in 1819 is due for publication in 2005.]ast:James Watt cs:James Watt da:James Watt de:James Watt es:James Watt eo:James WATT fa:جیمز وات fr:James Watt he:ג'יימס ואט id:James Watt io:James Watt is:James Watt it:James Watt mk:Џејмс Ват nl:James Watt ja:ジェームズ・ワット no:James Watt pl:James Watt pt:James Watt ru:Уатт, Джеймс simple:James Watt sk:James Watt sl:James Watt fi:James Watt sv:James Watt zh:詹姆斯·瓦特