Heron of Alexandria

Heron of Alexandria (hēr`ŏn) or Hero, mathematician and inventor. The dates of his birth and death are unknown; conjecture places them between the 2d cent. B.C. and the 3d cent. A.D. He is believed to have lived in Alexandria; although he wrote in Greek, his origin is uncertain. Several of his works survive either in Greek or in Latin translation. He wrote on the measurement of geometric figures, and a formula for finding the area of a triangle has been ascribed to him. Known for his study of mechanics and pneumatics, he invented many contrivances operated by water, steam, or compressed air; these include a fountain, a fire engine, siphons, and an engine in which the recoil of steam revolves a ball or a wheel.

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Heron of Alexandria

 or Hero of Alexandria

(flourished c. AD 62, Alexandria, Egypt) Greek mathematician and inventor. He is remembered for his formula for the area of a triangle and for inventing the aeolipile, the first steam engine, which, in his design, was a forerunner of the jet engine. Of his many treatises, one contains a method for approximating the square root of a number. His writings on mechanics include discussions of the five simple machines, mechanical problems of daily life, and the construction of many kinds of engines.