The Antikythera Mechanism

Τhe recovery of the Mechanism among the other objects from the cargo of the ship that sank off Antikythera (1900-1901) makes this shipwreck unique and of major importance. Seven large fragments (Α-G) and 75 minor pieces (1-75) have survived. Their exact position and the original structure of the Mechanism are still a matter of intense investigation. It contained at least 30 gearwheelsas well as dials, scales, axles and pointers. The Greek, astronomical inscriptions on the surface of the Mechanism refer to astronomical and calendar calculations, while the inscriptions on its metal protective plates contain instructions for its use. The Mechanism was protected by a wooden case, which had a bronze plaque on the front and the back side.
The Antikythera Mechanism is the earliest preserved portable astronomical calculator. It displayed the positions of the Sun, the Moon and most probably the five planets known in antiquity, Mercury, Venus, Mars,Jupiter and Saturn. It was used to predict solar and lunar eclipses, it kept an accurate calendar of many years, and displayed the date of Pan-Hellenic games that took place at Nemea, at Isthmia, at Delphi, at Dodona and at Olympia.
Its construction dates to the second half of the 2nd century BC. Its technology, which recalls the successors of Archimedes and the school of Poseidonius on the island of Rhodes