Galileo's pendulum clock, c 1642.

Reconstruction made in Florence in 1883 based on a drawing by Galileo's friend and biographer, Viviani, of an incomplete pendulum clock proposed by Galileo (1564-1642) just before his death in 1642. Galileo Galilei's design represents the first certain known attempt to apply a pendulum to control the rate of a weight- or spring-driven clock.