Historically, the idea that the stars and planets influence the Earth and its inhabitants has proved powerful in almost every culture, offering an important context for the use of mathematical and astronomical instruments. In the past, however, historians of astronomy have paid relatively little attention to astrology and other “non-scientific” topics, while historians of astrology have tended to concentrate on the analysis of texts rather than surviving artefacts, scientific instruments in particular. Heaven and Earth United is an attempt to redress the balance through an exploration of...