13.04.2018 | Who invented it: James Watt

A Scotsman generates steam

He is often hailed as the inventor of the steam engine. The fact is he merely developed a new model based on an old invention and the new one was considerably more efficient. By doing so, he facilitated the breakthrough of this revolutionary discovery: The Scotsman James Watt. He also came up with the concept of horsepower (HP) and the unit of measure for power output is also named after him.

In 1764, the instrument maker James Watt was asked to repair a steam engine model. By taking a closer look at the contraption, Watt identified defects in the model. He became fascinated with the machine and began experimenting ... a project that would change people's lives.

Watt was not the true inventor of the steam engine (see box). The model he used for his work was developed by Thomas Newcomen in 1710. It was the first steam engine suitable for the mass market. The engine was primarily used for draining in mining, but its efficiency was low and it used an enormous amount of coal.

James Watt

Watt noticed that the steam in the cylinder of Newcomen's model cooled off very quickly, resulting in poor thermal regulation. Watt constructed a model with a capacitor outside of the cylinder. The steam condensed more quickly, the cylinder stayed hot and the engine ran longer. Instead of using atmospheric pressure like Newcomen, Watt used steam alternating on both sides of the piston so that the engine would run more smoothly. With this discovery, he improved the engine's performance. Watt's model ultimately had an output of 3%, three times the Newcomen machine.

A sick child

James Watt was born as the son of a carpenter and draughtsman in the seaport of Greenrock on Scotland's west coast on 19 January 1736. He was a very sick child, unable to attend school regularly and primarily taught by his mother at home. He often helped out in his father's workshop.

At 18, he began a 7-year course of study in mechanics and instrument building in London but abandoned his studies after two years because he found it too boring. Owing to the strict guild laws in Scotland, he was not allowed to run his own workshop. In 1757, he secured a post at the University of Glasgow where he made instruments such as compasses.

Dependent on help

In 1769, Watt filed a patent application for his steam engine. He worked as a surveyor but had no regular financial income. As a result, Watt was dependent on the support of others to build his steam engine. Help came from the industrialist John Boulton with whom he founded the company Boulton & Watt in Birmingham (North England) in 1775. As a financier, Boulton acquired the rights of two thirds of the profits from the business with steam engines.

«He became fascinated with the machine and began experimenting ... a project that would change people's lives.»
James Watt's steam engine

After the patent expired in 1800, Watt slowly withdrew from the business and turned it over to his two sons.

Amiable and intelligent

Watt’s contemporaries described him as very sociable, modest, amiable and extremely intelligent. He married twice and had six children. By the time Watt died on 25 August 1819 at the age of 83, he was a very respected man. Although he did not invent but merely perfected the steam engine (see box), his work was a major driving force behind industrialisation. Moreover, designs for a steam ship by Robert Foulton (1807) and the steam locomotive by George Stephenson (1814) would not have been possible so quickly.

Watt also defined the physical term for workload and introduced horsepower as a measurement unit for output. In recognition of his great achievements he received an honorary doctorate from the University of Glasgow and was appointed to the Academy of Sciences in Paris. Physical output has been called watt since 1889, a term that can be found on every electric bulb. Watt’s heritage lives and shines on...

In the beginning

James Watt perfected the steam engine by Thomas Newcomen, 1663-1729. Newcomen used the findings of Thomas Savery, 1650-1715, who in turn based his inventions on the research of the Frenchman Denis Papin, 1647-1712, - the real inventor of the steam engine.

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