A quick summery: Ancient technology, used possibly as an astronomical and calendar calculator. Mechanically, it is a mechanism incorporating 32 gear-wheels as well as inscriptions related to the zodiac and the months. Discovered in 1900-1901 by sponge divers from Syme in an ancient shipwreck near the island of Antikythera. Dated to ca 80 A.D

The mechanism consisted of a box, the external faces of which bore metal plates that were scaled. On these plates and on the flaps of the box, various signs were engraved, as well as names of months, constellations, signs of the zodiac, names of the then known planets, winds, indications for the equinox and the times certain constellations appeared and disappeared on the sky .The mechanism laying in the box consists of 30 toothed wheels the diameter of which varies from 9 to 132 mm. The most impressive feature of the mechanism is its differential gear system accepting two different rotations. These toothed wheels were set in motion with the aid of a hand operating shaft and rotated at a different speed each, putting in motion in their turn other shafts and indicators on the scaled plates vesting the surface of the box. So this machine is showing the movements of the sun, the earth, the moon, and the main constellations in their different phases.