ABSTRACT
The first investigator to concern himself seriously with hydromechanical problems after the Renaissance was Simon Stevin, or Stevinus, of Bruges, a Flemish engineer and inventor who rose to high rank in the Dutch Army. Several of Galileo Galilei’s disciples extended their researches to include the mechanics of liquids and gases. Evangelista Torricelli was born in 1608 at Faenza, of a distinguished family. He went to Rome at the age of twenty and studied there under Castelli, the close friend of Galilei and propagator of his ideas. Christian Huygens did not restrict his investigations on pendular motion to the case of the simple pendulum, in which a particle is supposed to swing at the end of a flexible weightless thread. After Galilei’s researches had become known in northern Europe, M. Mersenne raised the question, according to what laws did extended bodies of arbitrary shape vibrate if free to turn under gravity about fixed axes.
