Roman Portable Sundials ─ The Empire in Your Hand

In a largely unscientific era, when maps were rarities, how did Romans envisage their farflung empire? By various means for certain, which Talbert now supplements in this novel study. He investigates a set of intriguing clues that to date have attracted minimal attention. They derive from a type of portable sundial unearthed throughout the Roman world. These are ingenious miniature instruments, crafted in bronze and fitted with adjustable parts to accommodate the changes of latitude likely to occur on long journeys - from Britain to Spain, for example, or from Alexandria to Rome, or even on a circular tour. As cultured Romans knew, to function effectively any sundial must be set for the latitude where it is used. So, for convenient rapid reference, these portable ones deftly incorporate a list of 20 to 30 names and latitudes of cities or regions specified by the maker or owner. As a result, the choices offer unique insight into the mental world-maps of individual Romans who between them somehow developed the capacity to visualize the empire latitudinally. While these sundials share features in common, in other respects designers clearly vied to create distinctive enhancements. Comparison with modern calculations demonstrates that the latitude figures listed are often incorrect, so the sundials may not tell the time reliably everywhere. But then the nature of Romans' time-consciousness (or lack of it) must be taken into consideration. Talbert raises the possibility that owners might prize these sundials not so much for practical use, but rather as status symbols attesting to scientific awareness as well as imperial mastery of time and space. In retrospect they may be seen as Roman forerunners of comparable Islamic and European instruments from the Middle Ages onwards, even of today's luxury watches which display eye-catching proof of their purchasers' wealth, sophistication and cosmopolitanism.

Richard Talbert is a Cambridge Classics graduate who taught in the United Kingdom and Canada before becoming Kenan Professor of History at the University of North Carolina, Chapel Hill, where he has established the Ancient World Mapping Center. His many books include The Senate of Imperial Rome, the collaborative Barrington Atlas of the Greek and Roman World, and Rome's World: The Peutinger Map Reconsidered.