Galileo's proposed escapement
Galileo's escapement is a design for a clock escapement, invented by Galileo Galilei.
While observing and timing with his pulse, the swinging of lamps in the cathedral at Pisa, Galileo realized that their apparent isochronicity could be used for timekeeping. We now know that the pendulum is approximately isochronous only for small amplitudes, but it was nonetheless a vast improvement on the crude verge escapements of the day, keeping time to perhaps 15 minutes in 24 hours.
- ^ See note n. 1 in Van Helden, Albert (1995). "Pendulum Clock". The Galileo Project. Rice Univ. Retrieved 2010-11-18.