"The Antikythera Mechanism is a unique Greek geared device, constructed around the end of the second century bc. It is known that it calculated and displayed celestial information, particularly cycles such as the phases of the moon and a luni-solar calendar. Calendars were important to ancient societies for timing agricultural activity and fixing religious festivals. Eclipses and planetary motions were often interpreted as omens, while the calm regularity of the astronomical cycles must have been philosophically attractive in an uncertain and violent world. Named after its place of discovery in 1901 in a Roman shipwreck, the Antikythera Mechanism is technically more complex than any known device for at least a millennium afterwards. ..."
Yesterday I pointed to a news release about this and as it happened, Nature had already published a letter from the research team about this. The above quote is part of the abstract of a 5 page letter on the subject of the Antikythera Mechanism. If you are at a university or your public library has a Nature subscription, you should be able to read the full text.
The bibliographic citation for this article is "Nature 444, 587-591 (30 November 2006)"