Museo Galileo
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Simon Stevin

Flemish scientist and engineer, worked for the Dutch government and applied his technological expertise as Quarter-Master General of the Army. Author of many treatises on astronomy, military engineering, and navigation, Stevin (or Stevinus) made essential, pioneering contributions to mechanics, enunciating the theory of levers, the inclined plane, and pulleys, and formulating the concept of the parallelogram of forces. Studied hydrostatics and observed that the pressure of a liquid is independent of the shape of its container. In mathematics, analyzed irrational numbers and was one of the first to introduce decimal fractions in Europe.