JAMES WATT'S STEAM ENGINE

     James Watt was born in 1736 at Greenock. After his apprenticeship in London he returned to Glasgow and worked within the precincts of Glasgow College. There he happened to repair a Newcomen engine. He observed that when every time water was injected to condense the steam in the cylinder it chilled the cylinder too. The next admission of steam had to reheat the cylinder. Naturally this was the cause of the poor efficiency of Newcomen engine.

     Watt developed an ingenious method to overcome this problem. Condensing of the steam was done in a separate vessel which was always kept cold and maintained vacuous by means of a air pump. The cylinder itself was surrounded by a steam jacket to maintain its temperature. After overcoming some problems regarding workmanship and tools the first viable steam engine was made in 1780. Later he made many more improvements in steam engine like converting the rectilinear movement of the piston and beam into a rotational movement of the shaft, and developing a “double-acting” engine in which steam was admitted to side of the piston in turn. He also invented a sculpting machine which was earlier called “the likeness lathe”.