The firm of Boulton and Watt, a partnership between Matthew Boulton and James Watt, made steam engines at their Soho Foundry in Smethwick, near Birmingham, England.
The oldest working Boulton and Watt engine is the Smethwick Engine.
Another working Boulton and Watt beam engine - dating from 1812 - can be found at Crofton Pumping Station.
The Powerhouse Museum in Sydney, Australia, houses the world's oldest working rotative steam engine, built by Boulton and Watt in 1785 to grind malt in Whitbread's London brewery.
