Pendulum Clock

Pendulum Clock

          Around 1602 Galileo Galiei notice that the swing period of the      pendulum was nearly independent of the amplitude of the oscillation,and this become the most important history of horology. in 1656 Dutch mathematician and astronomer christiaan as a regulating oscillator in a clock

    The swing period of a pendulum is only a function of its length and the local gravitational field,unlike the verge and balance oscillator,which it replace,which had an oscillation period that depended on the force exerted by the driving spring.

                         within years of Huygens's discovery, weight - driven  pendulum clocks were appearing all over Europe. To provide a sufficient distance for the weights to fall,and to accommodate a reasonably long pendulum -a two-second tick-tock requires a pendulum 3 feet long -these clocks were put in long floor-standing cases. these "grandfather" clocks were reliable to an impressive twenty seconds a day. around 1670 the invention of the anchor escapement led to improvement in timekeeping by enabling the amplitude to the pendulum oscillation to be reduce.

      In 1676 the more fragile dead-beat escapement was introduce to high accuracy regarding clocks. This escapement gave the pendulum a "push" only when it was near its vertical position.coupled with a pendulum made of bars of different metals (usually brass and steel), it ensured that the length did not change as the temperature changed. the accuracy improved to about one second per day, an important aid in the work of  astronomical observatories