360James Watt patents his improved steam engine
In January 1769, the Scottish engineer James Watt patented a steam engine with a separate condenser. It used far less coal than earlier engines, and with his partner Matthew Boulton, Watt built engines that powered mines, mills and factories. His work drove the Industrial Revolution, and the unit of power, the watt, honours him.
In 1763, James Watt, an instrument maker at the University of Glasgow, was asked to repair a model of a Newcomen steam engine. He noticed it wasted most of its fuel, because the cylinder was heated and cooled with every stroke.
In 1765, Watt had the key idea: condense the steam in a separate chamber, so the main cylinder could stay hot. He received his patent on 5 January 1769.
In 1775, Watt formed a partnership with the Birmingham manufacturer Matthew Boulton. Their first commercial engines began work in 1776. Watt later added improvements that turned the engine's motion into rotation, so it could drive machinery directly.
Boulton and Watt engines spread through mines, cotton mills, ironworks and breweries, freeing factories from the need to be near rivers. Steam power became the engine of the Industrial Revolution, and the unit of power, the watt, is named after him.
- 1765
- Watt conceives the separate condenser
- 1769
- Patent granted
- 1775
- Partnership with Matthew Boulton
- 1776
- First commercial Boulton and Watt engines
Sources: Science Museum · Britannica · University of Glasgow.