January 19, 1736: James Watt is born
James Watt (1736-1819)
Science: Engineering
Known for: Watt steam engine
Scottish instrument maker and inventor whose steam engine contributed substantially to the Industrial Revolution. He was elected fellow of the Royal Society of London in 1785.
Deciding at age 17 to be a mathematical-instrument maker, Watt first went to Glasgow, where one of his mother’s relatives taught at the university, then, in 1755, to London, where he found a master to train him. Returning to Glasgow, he opened a shop in 1757 at the university and made mathematical instruments (e.g., quadrants, compasses, scales). He met many scientists and became a friend of Joseph Black, who developed the concept of latent heat.
While repairing a model Newcomen steam engine in 1764 Watt was impressed by its waste of steam. In May 1765, after wrestling with the problem of improving it, he suddenly came upon a solution - the separate condenser, his first and greatest invention. Watt had realized that the loss of latent heat (the heat involved in changing the state of a substance—e.g., solid or liquid) was the worst defect of the Newcomen engine and that therefore condensation must be effected in a chamber distinct from the cylinder but connected to it. Shortly afterward, Watt took out the famous patent for “A New Invented Method of Lessening the Consumption of Steam and Fuel in Fire Engines”.
In 1782, at the height of his inventive powers, he patented the double-acting engine, in which the piston pushed as well as pulled. The engine required a new method of rigidly connecting the piston to the beam. He solved this problem in 1784 with his invention of the parallel motion - an arrangement of connected rods that guided the piston rod in a perpendicular motion - which he described as “one of the most ingenious, simple pieces of mechanism I have contrived”. Four years later his application of the centrifugal governor for automatic control of the speed of the engine, and in 1790 his invention of a pressure gauge, virtually completed the Watt engine.
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Article: “Watt, James”. Encyclopædia Britannica 2006 Ultimate Reference Suite DVD
Picture: “James Watt”. From Helmolt, H.F., ed. “History of the World”, New York, Dodd, Mead and Company, 1902.
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