John Wilkinson

John Wilkinson was an English ironmaster of the Industrial Revolution known for both precision cannon boring and, later, an 1774 boring machine that made the modern steam engine practical. His machine supported the boring bar at both ends rather than as an unsupported cantilever, letting him bore cast iron cylinders to a precision earlier machines could not match, which sharply reduced the leakage of steam past the piston. That precision won him an exclusive contract to supply cylinders to Boulton and Watt for their steam engines, without which James Watt's improved engine design could not have been built to a workable tolerance. Wilkinson expanded into lead and copper mining, a London lead-pipe works and canal investments, sponsored the world's first iron bridge at Coalbrookdale, and by 1796 controlled roughly an eighth of Britain's cast iron production.