While James Watt worked as a mathematical instrument maker at the University of Glasgow, he repaired a model of Newcomen’s steam engine.
Thomas Newcomen (1663 - 1729) designed the first practical steam engine to use a piston in a cylinder. His first working engine was installed at a coalmine in Staffordshire in 1712.
Newcomen’s engines became very successful, although they were inefficient and extremely expensive, costing around £1,000. Watt tried to improve the performance of Newcomen’s engine. After years of experiments, he tripled its efficiency and doubled the power.