The final date of the Antikythera mechanism

Abstract

The Antikythera mechanism is a mechanical astronomical instrument that was discovered in an ancient shipwreck (from about 60 bce) at the beginning of the twentieth century. A consensus does not exist on the question of whether the mechanism was built shortly before the shipwreck or significantly earlier. Nevertheless, there is an emerging consensus among scholars about the epoch of the back dials of the mechanism: the Saros dial would start at 27 April 205 bce and the Metonic dial four synodic months earlier, that is, at 25 August of the same year. Using these two starting dates together with the positions that some pointers still show in the extant fragments of the mechanism I calculate the final date of the mechanism (i.e. The date that it showed when it was last cranked, some time before the shipwreck) as approximately 5 March 193 bce or one anomalistic month earlier.