Boulton and Watt
James Watt (1736-1819) invented the separate condenser in 1769.
This was the first economic steam-powered engine. Not only were the new engines far more powerful than the old Newcomen engines but also their consumption of fuel was less than a third of the atmospheric engines.
This power output was effectively doubled yet again by Boulton & Watt who began to supply for their own engines to Cornwall from 1777. They also made highly significant fuel savings. During the last quarter of the eighteenth century, large scale copper mining attracted Boulton and Watt to Cornwall; a region that became their principal market. Their patent expired in 1800 and Cornish engineers went on to develop high pressure steam pumping technology which resulted in the Cornish beam engine and boiler, the most efficient equipment of its kind at that time anywhere in the world.