Today is the 115th anniversary of the Antikythera mechanism discovery.
The Antikythera mechanism is an ancient Greek analogue computer and orrery used to predict astronomical positions and eclipses. as well as a four-year cycle of athletic games that was similar, but not identical to, an Olympiad, the cycle of the ancient Olympic Games.
The device is a complex clockwork mechanism composed of at least 30 meshing bronze gears.
Source : Wikipedia.