The Scottish mechanical engineer and all-round tinkerer James Watt was born in Greenock in January 1736 AD, son of a prosperous shipwright and a well-educated mother. Watt was schooled at home by her until her death when he was 18. He left his ailing father to study instrument making in London, returning after a year to Glasgow to make his own fortune in his own company. There he gained some repute for building and repairing astronomical instruments for the University of Glasgow. Around 1764, Watt was given a Newcomen steam engine to repair, and he became infatuated with the potential of steam power.
Watt thought the design of the Newcomen, in use for 50 years to pump water from mines, was outdated, hopelessly inefficient, and unreliable. In 1769, Watt received his first patent for improvements to it. Then in 1775, Matthew Boulton of Birmingham joined Watt to create the firm Boulton & Watt, which soon became the most important "engineering" firm in England, supplying engines to fill the unrequited demand by paper, cotton, flour, iron, textile mills, as well as distilleries, canals, and waterworks. Wealthy beyond belief by 1800, Watt retired to devote himself to research, inventing the rotary steam engine, the double-action engine, and the steam pressure indicator. He died in 1819, still tinkering.
So pivotal was his role in industrial civilization that a unit of measurement of mechanical (and eventually electrical) power – defined as joules per second – was named for him, perhaps the ultimate honor for an engineer.