James Watt is the Scottish engineer and inventor who literally changed the world. His improvements to the steam engine drove the Industrial Revolution. His success was so great that the internationally recognised SI (Système international (d’unités)) unit of power was named the Watt in his honour.

The year 2019 marks the 200th anniversary of Watt’s death and the 250th anniversary of Watt’s patent (to use a separate condenser to improve the efficiency of a steam engine.).

You’ll find out more about Watt’s life below.



19 January 1736 – James Watt was born in William Street, Greenock – the son of a prosperous shipbuilder.

A family anecdote was that young “Jamie” (as friends called him) was fascinated by the sight of a steaming kettle. Sadly, his father’s firm hit problems and his mother died when he was just 17 years old. Watt realised he had to make his own fortune.

1755 – James set off for London to make mathematical instruments, returning to Scotland a year later. He struggled to find work and eventually was employed by university professors repairing academic instruments. For the next six years, he ran a business manufacturing musical instruments and toys at Glasgow University.

1758 – Watt was introduced to John (later Professor) Robison – and the science of steam.

1763 – Glasgow University asked Watt to repair one of its Newcomen steam engines, which Watt realised were terribly inefficient. He also teamed up with another University Professor, Joseph Black.

1764 – Watt married his cousin, Margaret Miller.

1765 – Out walking on Glasgow Green, Watt had his eureka moment. He realised that having a separate chamber for steam to condense would make a steam engine run faster and use less fuel. However, turning his idea into a working engine was more problematic. Watt was also deeply in debt.

Black introduced Watt to John Roebuck – an industrialist who helped found the Carron Iron Works in Falkirk. Roebuck was based at Kinneil House, near Bo’ness.

Roebuck paid off Watt’s debts in return for a two-thirds share of Watt’s invention. He also built him a cottage workshop beside Kinneil House to carry out his experiments away from the prying eyes of local people.

Watt is said to have worked at Kinneil for two spells in 1769 and 1770.

1769 – the idea of using a separate condenser to power a steam engine was patented. However, Watt struggled to get a working model constructed.

1773 – Watt’s constant supporter, his wife Margaret, known as “Peggy, died in childbirth. The couple had two other children.

1773 – His backer, John Roebuck, went bankrupt and was forced to pass on his interests in the steam engine patent to one of his associates, industrialist Matthew Boulton of Birmingham.

1774 – Watt, at the age of 38, moved to Birmingham to partner up with Boulton at a factory in the Soho area. Watt’s new English partner had the precision engineering to perfect Watt’s improved steam engine. Orders for improved steam engines rolled in, initially from collieries.

1776 – Watt married again, this time to Ann MacGregor and the couple had a further two children.

1781 – Boulton suggested other applications for their improved steam engines – such as flour, cotton and iron mills.

1784 – Watt made further improvements to the steam engine and patented a steam locomotive.

1800 – Boulton and Watt, now very wealthy and very famous, retired and handed over their business to their sons. Watt continued to invent other things before and after his retirement – including several machines for copying sculptures and medallions.

1816 – Watt made his last trip to his hometown in Greenock, arriving – appropriately – on a paddle-steamer.

1819 – August 19, Watt died, aged 83, at his home “Heathfield” in Handsworth, now part of Birmingham. He was buried alongside his business partner, Matthew Boulton, at St Mary’s Church, Handsworth.

During his lifetime, James Watt was elected a Fellow of the Royal Society of Edinburgh, and a Fellow of the Royal Society of London. He was elected to the Society of Civil Engineers (Smeatonians) and was made an Honorary Doctor of Laws at Glasgow University. He was also elected a Foreign Member of the Academie des Sciences in Paris.

He is widely credited as being a driving force behind the Industrial Revolution.

1882 – a unit measuring electrical and mechanical power was named a “Watt” in honour of the Scottish inventor.

2009 – the Bank of England announced that Boulton and Watt would appear on a new £50 note – the first time two people would feature on the back of an English banknote.

2011 – Watt was one of the first inductees into the Scottish Engineering Hall of Fame. New inductees are announced each year at the Institution of Engineers and Shipbuilders in Scotland (IESIS) James Watt Dinner

2019 marks the 200th anniversary of Watt’s death and the 250th anniversary of the granting of his patent for a new type of steam engine. The New Scientist magazine said the improvements devised by Watt “converted it (the steam engine) from a prime mover of marginal efficiency into the mechanical workhorse of the Industrial Revolution”.

Discover how James Watt is still making news today in our news section.