Pendulum clock designed by Galileo in 1642 and made by his son in 1649, model.

This 19th century model is based on a drawing made by Galileo's (1564-1642) friend and biographer Viviani (1622-1703) of a pendulum clock, which Galileo designed just before his death and which was partly constructed by his son Vincenzio in 1649. It represents the first known attempt to apply a pendulum to control the rate of a clock. Galileo had observed that the time taken for a pendulum to complete one swing was almost independent of the arc through which it swung and he had used a freely swinging pendulum to time various astronomical events. He recognised the potential of using a pendulum to control a clock but died before his work could be completed.