The Front Cover Inscription

The bronze plate known as the “Front Cover” of the Antikythera Mechanism had inscriptions on its outside face. This paper describes the reconstruction of the surviving parts of this text from the Mechanism’s fragments, giving transcriptions and translations. The texts give data on synodic cycles for the five planets, and it may be conjectured that lost lines described the behaviour of the Sun and Moon. The data strongly support the idea that planetary motions were displayed on the front face of the Mechanism using simple epicyclic or eccentric models. Previously unattested long and accurate period relations are given for Venus and Saturn, which are favourable for geared representation and probably of Greek, rather than Babylonian, origin.