Pendulum clock

Vienna regulator style pendulum wall clock

Pendulum clock designed by Galileo Galilei

A pendulum clock is a clock that uses a pendulum, a swinging weight, as its timekeeping element. It was invented in 1656 by Christiaan Huygens. From the year 1656 until the 1930s, the pendulum clock was the world's most accurate way of keeping time. This is what caused it to be used by a lot of people all over the place.It works on principle of periodic motion.