A Portable Cosmos is both an excellent focussed case study of an individual object and a comprehensive broader treatment of the relevant aspects of ancient science and technology. It is beautifully and thoughtfully illustrated, with numerous diagrams and photographs placed strategically throughout, not just of the mechanism but of various other relevant ancient objects such as calendar and other almanac-style parapegma inscriptions, manuscripts,
astrolabes etc. I shall definitely be adding it to the syllabi of my 'Nature and the Natural World in Antiquity' and 'Ancient Technology' courses, and I recommend that other instructors do the same.
Alexander Jones is Professor of the History of the Exact Sciences in Antiquity at New York University's Institute for the Study of the Ancient World.