Wristwatch/Timelines

3500 BC(E) - The Obelisk is created by Egyptians, and possibly previously by Sumerians.

1500 BC(E) - The Sundial/Shadow Clock built by Egyptians

1500 BC(E) - One of the earliest water clocks is buried in the tomb of Egyptian pharaoh Ahemhotep I

500 - 100 BC(E) - Romans and the Greeks improve water clocks through mechanics (bells, gongs, doors -- ways to attempt flow regulation)

325 BC(E) - clepsydras' ("water theives") are used by the Greeks

30 BC(E) - Vitruvius describes 13 different types of sundial styles in Greece, Asia Minor, and Italy

1 BC(E) - Andronikos constructs the Horologion, the "Tower of the Windows" in Macedonia, Athens Marketplace

200 - 1300 CE (AD) - Chinese inventors modify clepsydras' to drive various mechcanisms.

725 CE (AD) - A water escapement is invented in the far east

900 CE(AD) - Pocket sundials are employed

1088 CE (AD) - Su Sung implements a water escapement in the "Su Sung clock tower". It is over 30 feet tall and very elaborately adorned.

1300s CE(AD) - Mechanical clocks appear in Italian cities, in towers.

1500 - 1510 - Peter Henlein of Nuremberg invents the spring-powered clock.

1656 - Christiaan Huygens (Dutch) invents the first pendulum clock.