James Watt was born in Greenock, January 19, 1736 the fourth of the five children of James Watt (1698-1782) and Agnes Muirhead (1701-1753).
At fifteen, James had twice read Wilhelm van St. Gravesandes (1688-1742) book The Mathematical Elements of Philosophy (Gravesande, 1720) and had made numerous chemical experiments. He showed early signs of inventive ability and learned the trade of scientific instruments maker. In 1757, he took employment in this capacity at the University of Glasgow. At the university, he gained important practical knowledge from Joseph Black (1728–99), a professor of medicine whose discoveries laid the foundation for thermodynamics.
Of all the friends he made at this time the two who most deeply influenced his future were Black and John Robison (1739-1805), who first directed his attention to the steam engine.
Using Black’s concept of latent heat (that heat does not increase the temperature of boiling water but simply produces more steam), Watt dramatically improved the efficiency of Thomas Newcomen’s (1663–1729)steam engine.
Watt’s interest in the possibilities of generating power from steam appears to have been aroused before 1760, without being influenced by the engines available at that time. Together with Robison he carried out experiments with a Papin digester, in 1761 or 1762. He used a syringe with a plunger as a makeshift cylinder and piston and found that the pressure of steam from a digester was enough to cause the plunger to raise about fifteen pounds, a considerable weight.
This system, in which the steam pushes from both sides of the piston rather than from just one, enhanced efficiency and increased power. Watt’s invention helped to advance manufacturing and transportation and influenced later inventions.
The new engine was first patented in 1769.In 1775, the savvy entrepreneur Matthew Boulton (1728–1809) became his business partner. 1781, Watt and Boulton patented a “sun and planet” gear in order to create rotary motion from vertical motion, thus adapting the steam engine to power industrial machines grinding, milling, weaving.
The invention of steam engine by James Watt
