phase relationship.] Clock and Watch Escapement Mechanics http://www.abbeyclock.com/escapement.html http://www.youtube.com/watch?v=gIOd7Bpuw9U     From pendulum clock (Wikipedia, accessed 11/21/09): A pendulum clock is a clock that uses a pendulum , a swinging weight, as its timekeeping element. From its invention in 1656 by Christiaan Huygens until the 1930s, the pendulum clock was the world's