Steam Engine

Through its application in manufacturing and as a power source in ships and railway locomotives, the steam engine increased the productive capacity of factories and led to the great expansion of national and international transportation networks in the 19th century.

Watt’s steam engine. In Britain in the 17th century, primitive steam engines were used to pump water out of mines. In 1765 Scottish inventor James Watt, building on earlier improvements, increased the efficiency of steam pumping engines by adding a separate condenser, and in 1781 he designed a machine to rotate a shaft rather than generate the up-and-down motion of a pump. With further improvements in the 1780s, Watt’s engine became a primary power source in paper mills, flour mills, cotton mills, iron mills, distilleries, canals, and waterworks, making Watt a wealthy man.

The steam locomotive. British engineer Richard Trevithick is generally recognized as the inventor of the steam railway locomotive (1803), an application of the steam engine that Watt himself had once dismissed as impractical. Trevithick also adapted his engine to propel a barge by turning paddle wheels and to operate a dredger. Trevithick’s engine, which generated greater power than Watt’s by operating at higher pressures, soon became common in industrial applications in Britain, displacing Watt’s less-efficient design. The first steam-powered locomotive to carry paying passengers was the Active (later renamed the Locomotion), designed by English engineer George Stephenson, which made its maiden run in 1825. For a new passenger railroad line between Liverpool and Manchester, completed in 1830, Stephenson and his son designed the Rocket, which achieved a speed of 36 miles (58 km) per hour.