One of the most fascinating timepieces ever made are grandfather clocks. If you are wonderful how clocks like these tick, learn a thing or two about them today. Pendulum clocks have been used in keeping time since the mid-15th century. They have not changed dramatically since then.

The use of a pendulum generally swings once per second. In small cuckoo clocks, some pendulum might swing two times per second while in big grandfather clocks, the pendulum swings once every two seconds. Pendulum clocks were the first clocks made to have any sort of accuracy.