Of Sundials

The two rooms of the exhibition Time and Cosmos in Greco-Roman Antiquity which is now on show at the Institute for the Study of the Ancient World, New York, include much of interest for our project. Conceptions of time are often studied exclusively on the basis of written texts, but material remains such as sacred calendars and moulds for parapegmata (tables predicting the weather on the basis of constellations) illustrate some of the competing ways of measuring time in the ancient world. Among the objects on display are a number of portable sundials of the sort that are discussed in a new monograph by Richard Talbert. Some of these sundials include markings for cities spread across the Roman empire, thereby enabling the owner to track different hour-schemes at different points in the empire. They were perhaps not so much practical guides as display pieces, demonstrations of Roman control over the Mediterranean and of the owner’s attempt to control time.

The objects on which I want to focus here are not sundials themselves but their representation in two mosaics. The first of these (on loan from the Rheinisches Landesmuseum, Trier) dates from the third century AD. It shows a balding man with a white beard holding what looks like a large leaf folded at a right angle with six veins on either side. In fact it is a sundial, and it is on this basis that the exhibition identifies the old man as the sixth-century BC philosopher Anaximander. Anaximander is said by a number of sources (Diogenes of Laertius, Eusebius, the Suda) to have invented the gnômôn, a vertical rod whose shadow could indicate by its length and angle both the time of day and the time of year. A different tradition, recorded by Herodotus, held that ‘the Greeks learned about the sundial, its pointer, and the twelve divisions of the day from the Babylonians’, and some modern scholars reconcile the sources by supposing that Anaximander introduced the sundial from Babylon into Greece. It may be better simply to accept that we see a clash between two different ways of conceiving technological innovation: diffusion (typically from Babylon or Egypt) on the one hand, and the wise Greek inventor (prôtos heuretês or ‘first finder’) on the other.

Philosopher and sundial
Mosaic depicting philosopher with sundial, Rheinisches Landesmuseum Trier, 1907,724, 3rd century CE.

Whatever the origins of the sundial in Greece, the distinctive type of sundial shown in the mosaic poses a problem. The ISAW exhibition notes that it is a type first attested in the Hellenistic era and so an anachronism in a depiction of Anaximander. The problem posed by the mosaic is one that returns again and again in the study of ancient anachronisms: can one tell whether or not a particular temporal slip is deliberate? If an anachronism is unconscious, it seems simply to show a lack of interest in temporal change and so to offer support to the view that the Greeks lacked a developed historical consciousness. If an anachronism such as the mosaic’s sundial is conscious, on the other hand, it can be read as a pointed teleology, mapping out the later improvements set in motion by the inventor. But perhaps with the mosaic a third possibility should be mentioned. The anachronism may lie in our desire to find a specific name for a figure who is not after all identified in the mosaic itself. On the other hand, if the figure is the inventor of the sundial, the mosaic-maker has planted a small detail that debunks the tradition of the prôtos heuretês: given that the shadow cast by the leg of the chair on which the philosopher sits is so open to view, was the gnômôn – which protrudes at the same angle – really such a hard discovery?

The second mosaic in the exhibition comes (via the Museo Archeologico Nazionale di Napoli) from the Villa of Titus Siminius Stephanus at Pompeii (and so can be securely dated before 79 AD). It shows a group of seven men gathered around a sphere; one of the men is pointing at the sphere with a stick; and behind the whole group a sundial is perched on top of a column. The figures have often been identified either as members of Plato’s Academy (the stick-wielder would then be Plato himself) or as the Seven Sages, a group of wise men attested (with variations in their membership) from the time of Plato who were portrayed together in conversation (however implausibly) in works such as Plutarch’s Symposium of the Seven Sages. On either reading, the mosaic includes an anachronism: it shows an armillary globe, a sphere of rings representing the heavenly bodies – another Hellenistic invention. Rather than thinking of the identification as an alternative, we might prefer to see a deliberate blurring of Plato’s community with the archaic sages (perhaps with the seven figures corresponding to the seven Platonic planets). But there is also a way out of the anachronism. Study of other illustrations of globes led to the suggestion that the figure could be Aratus, the author of an astronomical poem in the third century BC, and this suggestion may in turn receive support from the recently published paintings from the ‘Tomb of the Philosophers’ at Pella, palace of Aratus’ patron Antigonus, in which a man pointing at a globe has been identified as Aratus. If the figure in the Pompeii mosaic is indeed Aratus, it is not the globe that is anachronistic but the grouping of seven men around it – a remnant of the archaic sage tradition.

Seven philosophers or sages
Roman Mosaic depicting seven philosophers or sages, with armillary sphere and sundial, Museo Archeologico Nazionale di Napoli 124545, 1st c. BCE-1st c. CE.

Is it a coincidence that these two anachronistic mosaics include instruments associated with the regular measurement of time? The development of new systems for technology can easily lead to nostalgia for simpler eras. Such nostalgia is uttered by characters in ancient comedy who complain that they have to eat at a time controlled by the movement of the sun, not by their own appetites. In the case of our mosaics, the anachronisms produce a more complex form of time that offers resistance to the increasingly precise temporal demarcation of Roman technology. The archaic Greek past serves as an idealised space, an object of wonder, not unlike that strange totality, Greco-Roman antiquity, to which the ISAW exhibition directs our delighted eyes.


Time and Cosmos in Greco-Roman Antiquity, Institute for the Study of the Ancient World, New York, October 19, 2016 – April 23, 2017. http://isaw.nyu.edu/exhibitions/time-cosmos/intro

  • R. Lane Fox, ‘“Glorious Servitude …”: The Reigns of Antigonos Gonatas and Demetrios II’, in id. ed., Brill’s Companion to Ancient Macedon (Leiden, 2011), 495-519.
  • R.J.A. Talbert, Roman Portable Sundials: The Empire in your Hand (New York, 2017).
  • R.J.A. Wilson, ‘Aspects of Iconography in Romano-British Mosaics: The Rudston “Aquatic” Scene and the Brading Astronomer Revisited’, Britannia 37 (2006), 295-336.

Author: Tim Rood

Researcher on ancient Greek historiography and its reception. Professor of Greek Literature, University of Oxford, and Dorothea Gray Fellow in Classics, St Hugh's College.

4 thoughts on “Of Sundials”

  1. I am not sure it would be anachronistic to represent Plato and his fellows at the Academy using armillary spheres (or other fairly advanced celestial models). Cf. the reference in Timaeus 40c-d referring to the use of ‘mimemata’ representing celestial motions: χορείας δὲ τούτων αὐτῶν καὶ παραβολὰς ἀλλήλων, καὶ [περὶ] τὰςτῶν κύκλων πρὸς ἑαυτοὺς ἐπανακυκλήσεις καὶ προχωρήσεις, ἔν τε ταῖς συνάψεσιν ὁποῖοι τῶν θεῶν κατ’ ἀλλήλους γιγνόμενοι καὶ ὅσοι καταντικρύ, μεθ’ οὕστινάς τε ἐπίπροσθεν ἀλλήλοις ἡμῖν τε κατὰ χρόνους οὕστινας ἕκαστοι κατακαλύπτονται καὶ πάλιν ἀναφαινόμενοι φόβους καὶ σημεῖα τῶν μετὰ ταῦτα γενησομένων τοῖς οὐ δυναμένοις λογίζεσθαι πέμπουσιν, τὸ λέγειν ἄνευ δι’ ὄψεως τούτων αὖ τῶν μιμημάτων μάταιος ἂν εἴη πόνος·


  2. We’ve received several comments by email on this post, which I summarise here. On the one hand, there is the view offered by art historians, that the depiction of philosophers and their accessories is a matter of the use of typical images from pattern books, and need not necessarily be an attempt to represent any specific individual. On the other hand, as Prof Betegh notes, there are passages in Plato where astronomical models or things resembling them are discussed – the Timaeus, Republic 10.616b-617d, the (spurious) Second Letter 312d – and yet matching what Plato mentions to the chronology of known instruments and models is not straightforward. Equally, a wide range of possible identifications for the philosophers of the Naples mosaic have been suggested, ranging from the Academy to the Lyceum to anachronic groupings of important figures in intellectual history. Textual evidence points to the chronological slipperiness of such figures, especially Solon and others included among the Seven Sages, so it is unsurprising that visual depictions of philosophers should raise questions for us about chronology temporality. We look forward to more discussion of these fascinating images both here on our blog, and in our project seminars and conference next year.


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