Huygens' Clocks  In 1656, Christiaan Huygens built the world's
first pendulum clock. It was far more reliable than any previous
mechanical timepiece. For nearly 300 years, the most accurate
clocks in the world all used pendulums, although many
improvements were made to Huygens' design in that period.
Christiaan Huygens was born in The Hague in 1629. His father,
Constantijn, was a famous statesman, scientist, poet and
musician. From 1645 to 1649, Christiaan studied at Leiden
University and Breda before returning home to the Hague. There,
he developed new ideas in mathematics, mechanics and optics. In
1655, he built a telescope with which he discovered Saturn's
rings and one of its moons. He also designed and built the first
working pendulum clock.  In 1666, Huygens moved to Paris to
become the director of the Académie des Sciences. While he was
there, he published the classic work Horologium Oscillatorium,
in which he gave a complete mathematical description of the
pendulum and a description of his improved p