Bryn Mawr Classical Review

This study provides a comprehensive view of various means of marking and measuring time in the Greco-Roman world (although references are also made to other cultures as well, notably the Egyptians and the Babylonians) and succeeds in outlining the main facets of this complex and rather daunting topic in a generally approachable manner. It is not structured around a unifying argument; rather, the chief goal of the author appears to have been to produce a synthesis based on the latest contributions to our understanding of how time was marked, measured and perceived in antiquity. This synthesis is meant to be occasionally -- but not pervasively or radically -- original in its explanations and textual interpretations. Classicists as well as historians of science will likely find it very helpful.

The first of the seven chapters of Time in Antiquity is a brief introduction that formulates the principal issues to be tackled in the rest of this study. It becomes clear from the first pages that Hannah is careful to avoid arcane terminology and unnecessarily intricate accounts of the topics at hand. Anyone who is interested in learning about this important aspect of everyday life in antiquity but is not well versed in mathematics or astronomy will find Hannah's style and general approach to be quite clear, although never diluted. Two dominant features of Time in Antiquity are introduced in this opening segment: the author's insistence on eliminating any possible modern misconceptions that we might bring along when trying to grasp the ancients' conceptions of time, and his constant emphasis on ordinary people's perception of time (hence his special interest in devices that mark and measure time), rather than on esoteric philosophical theories. In his attempt to reconstruct what he calls "the human facet of time-keeping and time-measurement" (3), Hannah relies on archaeological and epigraphic evidence and on an impressively extensive survey of texts (ranging from Homer, Hesiod and the Hippocratic corpus to late commentators such as Simplicius).

The second chapter, "Cosmic Time," reminds us how persistent certain images and formulas are despite the extraordinary progress of astronomy (e.g., we still speak of the rising and setting of the sun) and implicitly encourages us to assume the mindset of someone living, for instance, in classical Athens and taking advantage of prominent geographical features in order to mark the points where the sun rises at winter solstice and summer solstice. Understanding the relation between topography and the perception of time can help us to better appreciate historical data, such as the fact that Meton set up an astronomical instrument called heliotropion on the Pnyx. The Pnyx was not just the meeting place of the ekklesia but also the vantage point from which the Athenians could see the sun rise above Mount Lykabettos precisely at summer solstice. Again, Hannah does not assume any expert command of astronomy on the part of the readers and readily explains basic concepts that will then allow them to follow more easily his observations regarding the ancients' distinction between, e.g., solar calendar and lunar calendar, between the equator and the ecliptic, or the reasons for which the ancients would sometimes take into account the rising and settings of various stars and constellations (rather than just of the sun) in determining the right time for religious festivals or agricultural events. The 'competition' between lunar and solar periods in the Greco-Roman world (and implicitly the evolution of the very concept of month) is examined with due attention by the author, in order to bring into sharper focus its impact on social activities, on medical practices and on various forms of superstition. Analysis of the relevant Greek and Latin terminology and a plethora of etymologies (here and in other chapters) add further substance and clarity to this investigation.

The third chapter is devoted to how the Greeks and the Romans marked time. Itis centered on an elaborate account of the Antikythera Mechanism which correlates the motions of the moon, of the sun and of various 'fixed stars,' and indicates the signs of the zodiac and some stages in the Egyptian calendar. The invention of this complex contraption was originally thought to have been made possible by some of Hipparchos' discoveries, although it is now believed to be indirectly linked with Archimedes. As Hannah repeatedly points out, the purpose of this device remains a matter of speculation (despite our recently acquired ability, thanks to high resolution X-ray tomography, to see details, such as interlocking gears and Greek letters and words, that would otherwise remain completely concealed by mineral accretions). This, however, does not prevent him from providing relatively extensive accounts of the body of knowledge and set of beliefs that this mechanism seems to reflect. Consequently, he delves into a number of topics including the eight-year cycle or octaeteris and the Metonic or nineteen-year cycle (intended to overcome the difficulty of equating the incommensurate periods of the solar and lunar cycles). As he does elsewhere, Hannah illuminates ancient practices and methods by comparing them to notions that we are better acquainted with; for example, the sophistication of and need for the Metonic cycle is illustrated, among other things, by reference to major holidays (Passover, the Christian Easter, the Chinese New Year) whose positions in modern calendars are still determined by their relationship with certain phases of the moon. The zodiac's function to mark time through the solar year, the relevance of the Egyptian calendar to long-term astronomical calculations, the role of almanacs or parapegmata in keeping track of the solar year by pointing out star phases, and various comments on astrometeorology and reforms of the Roman calendar nearly complete this set of excursuses related to the Antikythera Mechanism. Still, the reader is in for a surprise towards the end of this chapter. After submitting the hypothesis that the main purpose of this device was probably astrological, Hannah, following Beck, notes that the Antikythera Mechanism, more than other devices, can be seen as a way of pointing to the intelligible order beyond observable heavenly bodies and phenomena and, by virtue of its dependence on numbers, is "a closer approximation of the Platonic, idealised conceptualisation of the cosmos" (65-66). He concludes that, from the time of Plato on, the purpose of the Greek astronomers "was to provide a theoretical basis, an overarching system, into which the observable phenomena, especially regarding the planetary system, could be fitted" (67). The argument for this rather tantalizing claim could be somewhat more elaborate, even if the author promised in his Introduction not to dwell at length on philosophical doctrines (only a couple of lines are devoted to Aristotle's Physics here). One wonders whether a longer discussion of seminal theories about the nature of time would not have been profitable in this context, at least in order to reveal their connections with various scientific theories and their common points with and telling differences from 'ordinary people's' perception of time.

The next two chapters are entitled "Telling Time" and "Measuring Time" and they convey the fascinating stories of the sundial and of the water clock respectively. The description of different types of sundials (plane, spherical, conical) is accompanied by a discussion of their particular advantages and disadvantages (e.g., the plane type of sundial is easy to construct, but difficult to mark out because of the projection of the dome of the sky onto a flat surface), of the connections between the evolution of sundials and that of calendars, and of the evolution of the concept of hour and its practical consequences. Ancient literary sources prove again to be extremely helpful in capturing concrete ways in which the ancients were trying to tell the time (e.g., by measuring the ratio between one's height and the length of one's shadow). The Eastern provenance of some of the techniques and instruments presented in the fourth chapter is treated with caution and helps us to place its central topic in a deeper cultural perspective. Equally interesting are Hannah's comments on the process of denaturisation symbolized and partly stimulated by the use of sundials (thus, Cassiodorus mentions that, unlike other species, humans could resort to artifacts, i.e. to sundials, in order to find out when it was time for dinner), and on the measure in which changes in society, politics (e.g. the establishment of city leagues) and warfare (conquests of immense territories) likely drove the development of timekeeping technology. Dials could be used to measure -- not just to tell -- time, but their quasi-universal flaw in this respect was due to the fact that hours were unequal throughout the year (since there were twelve hours before dawn and dusk and twelve between dusk and dawn, irrespective of the season). Water clocks, however, were more reliable timers, since their functioning obviously did not hinge on the motion of heavenly bodies, although they had other limitations, discussed in Chapter 5. The evolution of water clocks and other types of outflow timing devices from mere timers (measuring the amount of time allotted to activities such as speeches delivered in political or juridical contexts) to more complicated mechanisms, and the standardization of time that they entailed are at the heart of this chapter. Analysis of literary testimony is wonderfully combined here with technical description. Finally, Hannah stresses that the variable seasonal hour held sway throughout antiquity and into the Middle Ages (the subsequent invention of the mechanical clock consolidating the adoption of the equinoctial hour) partly because ancient ingenuity was absorbed too much by the search for a way to display seasonal hours, and less by the search for an instrument that would divide the day uniformly into equinoctial hours.

Chapter 6, "Conceptions of Time," is centered on the use of the sundial by the Greeks and the Romans. Although some of the material is imported from earlier chapters in the book, most of this chapter provides new angles from which we can fully appreciate the place of the sundials in the private and public spheres in antiquity. Hannah reemphasizes the near-ubiquity of this device in the ancient world by analyzing relevant artistic evidence and investigating a number of surviving sundials, whose likely mode of functioning he brings to life in minute detail. Of special interest in this context are, according to the author, the gradual introduction of shorter units of time (e.g., half-hours) and the transition from dials designed to lie flat on the ground or to be placed vertically on walls to dials set on a base in such a way that they are angled in alignment with the local latitude. In roughly the last third of this chapter we find a rather enthralling depiction of everyday life in Athens and Rome sub specie temporis. The structure of daily activities and routine -- especially for the Roman elite -- turns out to have hinged to a surprising extent on the division of day into seasonal hours. Some of the examples under scrutiny here are meant partly "to illustrate the differences between ancient and modern perceptions of time" (138-9. The chapter ends with an interesting glance at connections between geographical distance and the perception of time, as related to ancient postal systems, for example.

In the final and fairly short segment of this book, "Epilogue," Hannah moves on to consider aspects of the built environment in Rome that can cast light on the Romans' marking, measuring and perceiving time. Although he mentions the Golden House of Nero in this respect, he devotes most of his attention to the Pantheon, whose dome was presumably meant to symbolize the sky, i.e. the dwelling of the gods, the oculus in the dome serving "the same purpose as the hole in the roof of the spherical sundial" (152). This chapter, and indeed much of the book, is quite richly illustrated, the photographs, drawings and tables further enhancing the clarity of the author's descriptions, interpretations and reconstructions.

Hannah does not lay claim to an exhaustive study; indeed, some readers would probably prefer to see, the qualifications announced in the Introduction notwithstanding, more robust comments on philosophical theories and on the tension between and complementariness of divine time and profane time (to use M. Eliade's well known formulas). Even some points that are crucial to the central topics of this book are maybe too laconic; for instance, Hannah's own view (p. 95) concerning the early evolution of the sundial would probably benefit from more detailed elaboration. That said, Time in Antiquity is quite an achievement, relying on a vast bibliography and on an impressive wealth of archaeological evidence, as well as on the author's interpretative acumen. Classicists interested in virtually everything from the history of private life in antiquity to ancient architecture, as well as historians of science and technology, will find this synthesis very helpful and quite enjoyable.