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This Boulton & Watt engine was the first full-sized engine acquired for the collections and is one of the oldest surviving beam engines in the world.

Boulton & Watt engine fact file



Made in

Southwark, London, England

Made by

James Watt

Made from

Wood, metal


Height 9.5m, length 9.5m, width 5m


20 tonnes

Museum reference


On display

Explore, Level 1, National Museum of Scotland

Did you know?

The unit of power the watt is named after the Scottish inventor of the engine, James Watt.

Boulton and Watt engine

The Boulton & Watt engine was built in 1786 to pump water for the Barclay & Perkins Brewery in Southwark, London. Made double-acting in 1796, it was then capable of grinding barley and pumping water.

At that time, no one else could supply a steam engine that performed both these actions at once. With some minor modifications, it remained in service at the brewery until 1884.

Detail of Boulton and Watt engine

Detail of Boulton and Watt engine

Detail of Boulton and Watt engine

Detail of Boulton and Watt engine

Who was James Watt?

James Watt (1736-1819) was a prolific inventor, surveyor, instrument maker and engineer. His engines dramatically increased the power that could be generated through steam.

By entering into partnership with the Birmingham magnate Matthew Boulton in 1774, James Watt was able to channel the vast resource of Boulton’s Soho Foundry. Their partnership was so successful that the Boulton & Watt firm supplied engines and expertise to countries as far a field as Russia and Greece.

Statue of James Watt

Above: Marble statue of James Watt, including plinth, by Sir Francis Legatt Chantrey, 1827 - 1832, on display in the Grand Gallery at the National Museum of Scotland. On loan from the Heriot-Watt University Museum and Archive.

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