The Greeks and Romans lived according to a distinctively Hellenic conception of time as an aspect of cosmic order and regularity. Appropriating ideas from Egypt and the Near East, the Greeks integrated them into a cosmological framework governed by mathematics and linking the cycles of the heavenly bodies to the human environment. From their cosmology they derived instruments for measuring and tracking the passage of time that were sophisticated embodiments of scientific reasoning and technical craft, meant not solely for the study of specialists and connoisseurs but for the public...