1     Introduction

Geography is a broad and diverse area of study, a large tree with many branches. The different branches are so different that they tended even in antiquity – with less subject specialisation and more polymaths – to be pursued by different people. The main types are (i) human geography, focussing on the landscape of human life; (ii) physical geography, focussing on the land, sea and sky; and (iii) mathematical geography, focussing on mathematical modelling of aspects of physical and human geography. Where geography and biology meet, we now have ecology and environmental science. This tends in ancient authors to be dealt with under biology and agriculture. The more sophisticated works, such as Theophrastos’ works on botany, consider the effect of geology, soils and microclimates on plant physiology and growth.

Ptolemy practiced mathematical geography, and his reconstructed maps often feature as frontispieces in modern books on the history of geography. He scorns human geography of the type written by his predecessor Strabo, much as Thukydides scorns his predecessor Herodotos’ type of history. We won’t push the analogy while noting that Ptolemy’s Geography is about as much fun to read as a telephone book, which it resembles, strongly. Strabo, for his part, complained that his predecessor Poseidonios’ On the Ocean has too much mathematics and astronomy in it for geographers like himself (so too for would-be writers of geography like Cicero)¹. As with other fields in ancient science, practitioners were keen to carve out their own territories and make distinctions between what they thought and what their predecessors and contemporaries had written.

Those, like Ptolemy, who went in for mapping and mathematical modelling were often better known as astronomers, and were few and far between. Those, like Seneca, who concentrated their efforts on physical geography tended to pursue it as a part of natural history, especially physics/cosmology. Seneca includes some apparently gratuitous sex and/or violence scenes², perhaps added for the same sort of reasons as modern film-makers include them³. What we would call human geography was by far the most popular of the three types, combined with a strong interest in the flora and fauna of foreign places.

In keeping with its broad range and scope, geography connects to many other areas of Greek science. Physical geography theories were inseperable from general philosophical positions (a point made repeatedly and forcefully in all contexts by French in Ancient Natural History). Physical geography related strongly to one’s view of the cosmos and man’s place in it. In many societies nature and the forces of nature are expressed as gods: the Greeks had Gaia for earth, Ouranos for sky, Tartaros for the underworld; Zeus for lightning, Poseidon for storms, floods and earthquakes⁴ and so on. One’s general philosophy in return determined one’s response to the world. For example, Seneca, a Roman Stoic (which means a pragmatic man in a pragmatic culture⁵), aimed to remove fear of the unnatural and the inexplicable, such as earthquake, flood, lightning and other terrifying phenomena of nature, by rendering them natural and explicable. These natural explanations were all liberally peppered with Stoic philosophy in the form of reminders that we are all mortal, and that if one cannot prevent something bad happening, then there is no point fearing it.

As physical geography was useful to philosophers and moralists, human geography was useful to empire builders and administrators. The Royal Road of Persia from Susa to Sardis was mapped out long before the Ionian revolt (Herodotos 5.52-53), though Strabo credits Anaximander with the first published map (1.1.11); Alexander’s bematists’ principal function was, as their name reveals, to measure distances between places to be conquered and places conquered (Pliny NH 6.61.4); and Agrippa’s map (see Pliny NH 3.17) was connected with the demands of secure domination and taxation of the areas thus mapped⁶. For Strabo, ‘the greater part of geography subserves the needs of states’ (1.1.16 C9). Specifically, he says, it enables governors to manage their affairs in a better way by telling them how large a country is, how it lies, and what peculiarities of sky or soil are there⁷; it enables hunters to fare better knowing the character and extent of the forest; it enables commanders sensibly to pitch a camp, set an ambush, or direct a march in unfamiliar territory; and most importantly, it can save military expeditions from disaster arising from geographical ignorance of the areas into which they moved (citing many examples of costly blunders)⁸.

The group who were both consumers and producers of geographic knowledge, whom Strabo ignores in this section, were the private and state-sponsored seekers of exotic goods. These people are usually called traders, though that appellation overlooks two important things. Firstly the requirement for the early adventurous types, producers of geographic information, to be able to defend themselves, from whoever and whatever they might meet; and secondly the ancient habit of fighting for what they sought with whoever had it, rather than bargaining for it. Egyptian expeditions into the desert or other countries for metals, jewels, woods etc. were military campaigns⁹. Early Greek voyages of discovery and exploration were conducted by men who might otherwise be known as heroes or pirates¹⁰. When Nero sent an expedition (c. AD 60) south to Ethiopia, the reconnaissance of the upper Nile was conducted by a tribune and centurions of the Praetorian Guard (Pliny NH 6.181). Marcus Aurelius’ embassy to China in AD 166, apparently sent to try to obtain some silk worms, offered to the Chinese Emperor Huan-ti ivory, rhinoceros horns and tortoise shell but no jewels, ‘which fact throws doubt on the tradition’ said the author of the Chinese annal recording this embassy¹¹. Whether the Romans did offer anything, and if so what, we know not, but we do know that the Chinese did not give up any of their precious moths, and finally the insect was smuggled out to the West under Justinian (Procopius Secret History 8.17).

A relatively large part of ancient geographical knowledge survives, in whole or in part, largely because it has been found useful and worth keeping by many people in the intervening centuries. Many of the descriptive type geographies, which are the most readable and entertaining parts of the corpus, are compilations, based on information given by anonymous men over centuries; indeed, the authors of a fair number of these texts are not known, and so the works are assigned to Anon.. Many of the authors whose names survive did not discover or create the knowledge they relate, but organised, assessed, and integrated pre-existing and new knowledge. And they are self-conscious of this fact and their role. Eratosthenes, for example, commented upon the significant enlargement of geographical knowledge during and following Alexander’s conquests (Strabo 1.3.3). Strabo emphasizes that the expansion of the Roman and Parthian empires has extended geographical knowledge, and that integration of this new information requires some modification of old ideas – even a few ideas advanced by those of his predecessors for whom he has the greatest respect (1.2.1).

Similarly, the problems he noted in his ‘Note on books’ (pp. 392-4) still apply: ‘various writers do not always agree, of course, and the difficulty is to get an intelligent survey of what matters in this vast mass of scattered detail…some writers have been much edited like Herodotus, but others, including the most important, Strabo and Ptolemy, are not nearly so familiar or so fully explained…the usual histories of philosophy are partly relevant, though most pay too little attention to the matter in question, for instance the earth-globe, how it was first conceived and presently applied to geography. Such things are handled more for their own sake elsewhere [refs. to astronomical studies]…Ancient geography is sometimes handled as part of general histories of geography…or it may be treated, without the theory, as part of histories of exploration…in general histories of all science the subject is often too slightly and sometimes uncritically handled…all good histories of the ancient world are relevant, of course…but…it is strange how seldom they [ancient historians] think of giving a contemporary map or description (if they did, they would sometimes be less ready to assume distant trade and trade-routes)…There is much bearing on trade and travel in economic histories.’ This is a fair summary of the situation today, particularly with regard to the neglect of the subject by classicists, ancient historians, and ancient philosophers.

However, the problems have been compounded by the growth in the number and variety of publications produced by a much larger number of academics working in a much larger and more diverse world of higher education. Since Thomson wrote, Islamic, Indian, Chinese and other regional-based disciplines have revealed new sources and evidence from their parts of the world which are relevant to Greco-Roman interaction with them. These, needless to say, present a rather different picture to that painted by the still unfamiliar Greek sources. Then there are new relevant topic-based disciplines, such as oral history, folklore studies, and communication studies. Even anthropology, which has much to offer in terms of cross-cultural perception and communication, was a rather new and uncertain subject when Thomson wrote. Meanwhile physical geography and mathematical geography have changed almost beyond recognition since he wrote; platetectonics, catastrophic event horizons, and volcanology, for example, all have something to offer the modern student of ancient geographical studies¹³. It becomes ever more difficult to analyse and synthesize the subject.

We will take geography in the broad branches set out in the introduction.

2     Human geography

The Greeks’ interest in other peoples and other places is apparent from the first. Homer’s listing of contingents on both sides of the Trojan War continues with, for example, Delphi’s role as geographic centre and database in the days of colonisation, Kolaios’ discovery of Tartessos, Herodotos’ very wide-ranging interests and travels, Pytheas’ circumnavigation of Britain and exploration of the Baltic, Alexander’s recruitment of the Indian philosopher Calanus to his court, and Plutarch’s speculations on possible inhabitants of the moon.

A significant number of texts are entitled periplous or periegesis, meaning a sailing round or a walk across¹⁶. These texts are designed to be used by travellers. Their principle of organisation is a journey around or across a part of the world, discussing places in the order in which one would come across them as one travelled the coast or the road, like a very simple and summary Blue Guide. Some of these explorers, notably Pytheas, recognized the importance of astronomical observations in terrestrial location-finding, and went out of their way to record e.g. daylight hours at the solstice or equinox, or the height of the sun above the horizon at the same¹⁷. Phenomena like the sun moving in the ‘wrong’ direction (Herodotos 4.42, on the voyage sent out by Pharoah Necho to circumnavigate Africa) were unmissable, even by the most unobservant and disinterested crewman, and needed no special effort to note or remember¹⁸.

Conquerors and traders found the sort of information gathered by travellers extremely useful, and what we would call human geography early had very obvious practical applications. We noted above the more obvious military and imperial applications. As for the traders, an awareness of far-flung regional specialities in, and the supply of exotic products (natural and man-made) to, Theophrastos’ Athens (C4) is exemplified in his stereotype of ‘the obsequious man’ (Characters 5.9): ‘He is apt to keep a pet monkey, and buys a pheasant, and some Sicilian doves, and dice made from gazelle horns, and oil flasks from Thurii of the rounded sort, and walking sticks from Sparta of the twisted sort, and a tapestry embroidered with pictures of Persian soldiers, and his own little palaistra with sand and handball court’¹⁹. The ‘man of petty ambition’ has an Ethiopian slave (21.4) and a Melitian dog, to which, when it dies, he raises a monument with name plaque (§9).

To give some idea of the range and scope of texts in human geography, I will discuss briefly four works. Two are early, two are from the C1 AD, and only one of them was written by someone now thought of as a geographer.

The earliest surviving geographical text, though it survives only in fragments, is about one of the fartherest-flung places from Greece. It is the Indika written by Skylax of Karia in the C6 BC. It is mentioned by Herodotos (4.44). This was motivated by a conqueror’s interests. Skylax was a Greek mercenary in Darius’ service. This Persian King conquered part of the Indus river region c. 515 BC – about two hundred years before Alexander repeated the achievement – and twenty-five years before he turned his attention to the West and invaded Greece, to face Aiskhulos and his compatriots at the battle of Marathon. This treatise apparently was the report of an expedition which set out to follow the Indus from its headwaters to its mouth. Skylax commanded the fleet.

Hekataios of Miletos, one of the prime movers in the Ionian Revolt, wrote a Periodos which survives only in fragments. This was a first in two senses: it was the first attempt at a systematic description of world, and it was one of the first pieces of literature to be written in prose rather than poetry²⁰. Book 1 (Europe) covered the Mediterranean coast and islands, and set the paradigm for the periplous as a genre; book 2 (Asia, which included Africa) gave an outline of the rest of world as known to Hekataios and his sources in the early C5 BC. The first volume focussed on the coastal area but made some reference to inland tribes; the latter seems to have included reference to all the provinces of the Persian empire²¹.

Strabo ²² of Amasia (Pontus) was born around 65 BC, and died sometime after AD 21. His Geography is generally reckoned to be the best ancient geographical treatise to survive – best with respect to the structure of the work, its comprehensiveness and its interest. It was written just after Augustus’ death, and is an excellent source on Augustan organisation of the empire. The first 2 books concern the views of his predecessors, especially their theories on physical geography, and are immensely valuable for modern reconstructions of those earlier contributors to the subject. 15 books follow, working systematically around the oikumene, the inhabited world as known at the time. There are many historical digressions within the text, which reflect Strabo’s previous interest and (now lost) work, Historical memoirs, which filled 43 books. This history covered the period from the destruction of Carthage and Corinth (where Polybios stopped) to the death of Caesar or the battle of Actium. Had this work survived, Strabo might now be known as a historian rather than as a geographer.

The anonymous Periplous of the Erythraian Sea²³ is a manual for traders operating around the Red Sea, East African coast, and across the water to India; it is not a geographical treatise as such. It is fascinating particularly for the lists of trade goods imported and exported at each port mentioned, and it was evidently written by a practising merchant, probably in the C1 AD. For example, in the Indian town of Barygaza²⁴ the reader is advised (§49) that there is a good market for: wine – Italian wine is preferred here, failing that, Laodicean and Arabian; copper, tin and lead; coral and topaz; thin and inferior clothing of all kinds; bright coloured cubit wide girdles; storax and sweet clover; flint glass, realgar (an inorganic red pigment), antimony, gold and silver coins – which can be exchanged for the money of the country at a profit; and cheap ointment in small quantities. The reader is advised to bring for the local ruler expensive silver vessels; boys who can sing; beautiful women to add to the harem; fine wines; quality thin woven clothing; and the best ointments. Such gifts are presumably meant to earn the ruler’s goodwill or pay the local sales tax. In return, the trader will find here for sale spikenard (aromatic herb from the Himalayas), costus (spice from Kashmir), bdellium (aromatic tree gum), ivory, agate, carnelian, lycium (variety of Himalayan berberis used for pigment and medicaments), cotton cloth of all kinds, silk cloth, mallow cloth (rough local cloth), yarn, long pepper, and other local produce. Besides trade goods, we hear of an official pilot service for ships wishing to navigate the mouth and river Nammadus (modern Narmada) up to Barygaza (§42-4). The area appears to have been subject to tidal bores, making it extremely difficult and dangerous, especially for non-local crews and vessels (§46). According to Schoff (Periplous p. 183 n. 45), in the Gulf of Cambay ordinary tides rise and fall by 25 feet, and move at 4.5 to 6 knots. High spring tides can rise and fall 33 feet, and run at 6 to 7 knots. For sailors more familiar with the almost non-tidal Mediterranean or Red Seas, this phenomenon would have been particularly shocking.

3     Physical geography

Discovering the size and shape of the earth tended to be in the province of mathematician/ astronomers like Ptolemy or polymaths like Eratosthenes²⁵. The rest of what we call physical geography received attention usually under the heading of Meteorology. This concerned not just the weather and comets but also (despite its title) down to – or even in – earth subjects like earthquakes, volcanoes, the tides, the formation of minerals and metals, and physical/chemical change generally. But as the bedrock on which all natural history exists, the earth itself is the subject of numerous comments and sections in many general ‘natural philosophy’ texts (e.g. Seneca’s Natural Questions), general geography texts, history texts, and even theological writings. For example, our knowledge of Xenophanes’ association of fossilized fish, other marine animals and marine plants found in rocks with changes in sea-level and the deposition of dead bodies in mud which in due course turned into stone, is thanks to Hippolytus mentioning it in his Refutation of all heresies²⁶.

Specific texts addressed specific issues, like Theophrastos’ On Stones (surviving complete), On Weather Signs (surviving²⁷), On Metals (few fragments only), On Water (lost) or Meteorology (surviving in Syriac-Arabic translation²⁸). As ancient ‘scientists’ were polymaths and knew their ‘arts’ literature, so ‘lay’ people were reasonably au fait with at least some scientific theories. Consider Philostratus, an art historian, and even more significantly the artist whose picture he is discussing:

‘The two islands next to these [islands] were formerly both joined as one, but having been broken apart in the middle by the sea its two parts have become separated by the width of a river. This you might know from the painting my boy; for you doubtless see the two severed portions of the island are similar, and correspond to each other, and are so shaped that concave parts fit those that project. [Mainland] Europe once suffered the same experience in the region of Thessalian Tempe, for when earthquakes laid open that land, they indicated on the fractures the correspondence of the mountains one to another, and even today there are visible cavities where rocks once were, which correspond to the rocks torn from them, and moreover, traces have not yet disappeared of the heavy forest that must have followed the mountain sides when they split apart, for the beds of the trees are still left. So we may consider that some such thing happened to this island.’²⁹

Ancient ideas on physical geography generally have received little attention in modern times, but there is much here of interest. For example, Aristotle weighed equal volumes of salt and fresh water and knew that salt water is heavier. He theorized that the ‘earthy stuff’ (salt and other unknowns) in sea water ‘thickened’ its ‘consistency’, increasing its bouancy. He described a simple experiment to do at home to demonstrate this: make a strong brine and an egg will float in it³⁰. ‘Again if, as is fabled, there is a lake in Palestine, such that if you bind a man or beast and throw it in it floats and does not sink, this would bear out what we have said’ he adds correctly³¹. Turning from water to wind, his idea that hot and cold winds existed and sometimes blew underground – and were responsible for the formation of metals and minerals, for earthquakes³² and other subterranean phenomena – may be re-examined in light of the recent discoveries of (i) an unexplained hot wind which vents from the mouth of the Lechugilla cave in New Mexico and (ii) the hot water vents of the world’s oceans. Many volcanic regions have fumeroles and other vents through which hot gases and steam excape from below, depositing sulphur and other minerals around the hole, and it is not surprising that someone like Aristotle noted their existence and speculated on the existence of ‘underground winds’ of which these were surface manifestations.

The anonymous author of Aetna³³, written sometime before Vesuvius erupted (for that volcano is described as inactive) has very graphic and very detailed descriptions (in Latin verse) of eruptions of Aetna³⁴. This includes pre-eruption seismic activity, ‘thick fluid’ and bitumen flows, violent ejection of rocks large and small, liquification of soils, mudflows, lava flows, ash clouds, and of course the explosive violence of fire and flame. The author is as concerned to explain these phenomena in a scientific way as he is to describe them³⁵. Aristotle’s theory of underground winds forms the basis of the explanation, but it is well developed here³⁶ and constantly related to observation. This is natural history in the style of modern coffee-table books and natural history television programmes, but with an explicitly theoretical and argumentative edge. It is also from an age without photographs, when images had to be described, and scenes had to be pictured in the mind on the basis of that description. Picture the scene:

‘a thousand fires in a moment of time will set before you the true cause [of Aetna’s eruptions]. Facts and your eyes instruct you…a cloud of burnt sand is driven in a whirl; swiftly rush the flaming masses; from the depth foundations are upheaved. Now bursts a crash from Aetna everywhere: now the flames show ghastly pale as they mingle with the dark downpour. Afar off even Jupiter marvels at the mighty fires and trembles speechless in his secret haunt, lest a fresh brood of giants be rising to renew long-buried war, or lest Pluto be growing ashamed of his kingdom and be changing Tartarus for heaven; while outside all is covered with heap upon heap of rock and crumbling sand. They come not so of their own accord: unsupported by the strength of any powerful body they fall. It is the winds which arouse all these forces of havoc: the rocks which they have massed thickly together they whirl in eddying storm and roll from the abyss. For this reason the rush of fire from the mountain is no surprise. Winds when swollen are called ‘spirit’ (spiritus), but ‘air’ (aer) when sunk to rest. The violence of flame unaided is almost ineffectual; true, fire has always a natural velocity and perpetual motion, but some ally is needed for the propulsion of bodies. In itself it has no motive energy (impetus): where spirit is commander, it obeys. Spirit is emperor: fire serves in the army of this great captain (190-218) …As soon as it stirs its forces, and threatens havoc, it flies in different directions, dragging at once the soil with it: [there follows a short section of corrupt text with lacuna] while the eruption is announced by a deep rumbling underground accompanied by fire. Then shall you think fit to flee in panic and yield place to the divine event. From the safety of a hill you will be able to observe all. For of a sudden the conflagration blazes out, loaded with its spoils; masses of burning matter advance; mutilated lumps of falling rock roll forth and whirl dark shoals of sand. They present vague shapes in human likeness…then any stone that a surface fire has liquefied becomes, when the fire is quenched, more rugged–a sort of dirty slag like what you see drop from iron when smelted…the lava liquid begins to boil hotter and at last to advance more in the fashion of a gentle stream, as it lets its waves course down the slopes of the hill. By stages the waves advance some twice six miles³⁷. Nay, nothing call recall them: nothing checks these determined fires: no mass can hold them–’tis vain: all is war together. Now woodland and crag, here again earth and soil are in the flood. The lava-river itself aids their supplies and adjusts the compliant material to its own course…the lava-streams come to a standstill inside their margins and harden as they cool; slowly the fires shrink and the appearance of a waving harvest of flame is lost. Each mass in turn, as it stiffens, emits fumes, and, dragged by its very weight, rolls on with enormous din; whenever it has crashed pell-mell into some solid substance which resounds with the impact, it spreads abroad the fires of the concussion and shines with white-glowing core wherever it has been opened out. A host of sparks flash forth at every blow: the glowing rocks (look, you see the flashes in the distance–look, raining down in the distance!) fall with undiminished heat (462-507) …But in vain I try to marshal each effect with its determined cause if a lying fable remains unshaken in your mind, leading you to believe that it is a different substance which liquefies in fire, that the lava-streams harden in virtue of their cindery property, or that what burns is a mixture of sulphur and glutinous bitumen. For clay also, they assert, can fuse when its inner material is burnt out, and potters are a testimony to this: then by the process of cooling it recovers its hardness and tightens its pores. But this analogous indication is unimportant–an ineffectual reason given on hasty grounds. An unfailing token makes the truth evident to you. For as the essence of gleaming copper, both when fused with fire and when its solidity is unimpaired, remains constant and ever the same, so that in either state you may distinguish the copper portion, in no other way the lava-stone, whether dissolved into liquid flames or kept safe from them, retains and preserves its characteristics, and fire has not ruined its look (511-526) …The lava-stone is rigid; its surface barrier resists all fire, if you seek to burn it with small fires and in the open air. Well then, confine it in a narrow white-hot furnace–it cannot endure or stand firm against that fierce foe. It is vanquished: it relaxes its strength; in its captor’s grip it melts. Now, what greater engines, think you, can skill apply with the hand, or what fires can it support with our human resources to compare with the mighty furnaces with which Aetna burns, ever the mother of secret fire? Yet her fire is not of the limited heat within our own experience, but more akin to that of heaven or the kind of flame with which Jupiter himself is armed³⁸. With these mighty forces is allied the gigantic volcanic spirit forced out of straightened jaws, as when mechanics hasten to pit their strength against masses of natural iron, they stir the fires and, expelling the wind from panting bellows, rouse the current in close array. Such is the manner of its working: so goes far-famed Aetna’s burning. The earth draws in forces through her perforations; volcanic spirit compresses these into narrow space, and the path of conflagration lies through the mightiest rocks.’ (550-568 Duff trans.)

Some ancient descriptions of volcanic eruptions³⁹ are accurate for the kind of eruption witnessed and televised, with top-quality videos made by volcanologists, at Mount St Helens in 1980⁴⁰. On the basis of the archaeological evidence it is now clear that when Vesuvius destroyed Pompeii, Herculaneum, and Pliny the elder, whose eagerness to observe this event cost him his life (as Mt St Helen cost one volcanologist⁴¹ and about 60 other people their lives), it erupted in much the same way as Mt St Helen did⁴². Until 1980, just how far and how fast a pyroclastic volcanic ash cloud could move was not well understood, nor what was a ‘safe’ distance⁴³.

Poseidonios of Apameia in Syria was a distinguished and influential philosopher of phusis⁴⁴, chief exponent of what we call the Middle Stoa, who included a lot of geographical material in his writings⁴⁵. He may have been a major influence on the author of the Aetna. He is cited more frequently by Strabo than any other author, and was the main source⁴⁶ for Pliny in book 2 of the NH. He knew men in the highest circles of Republican Rome⁴⁷, being personally acquainted with Cicero and Pompey, though he lived in Rhodes and only visited Rome periodically (the first time he went was as ambassador for his adopted country, Rhodes).

He travelled widely – which does not mean frequently. One journey was to southern Spain, the outward leg apparently via the coast of France, and the return leg, which took three months, wandered between Sardinia and the North African coast. It may not be coincidence that his friend Pompey started his pirate campaign at Gibraltar and swept eastwards, driving pirates onto whatever shore they fled, or further along the Mediterranean⁴⁸. The naval forces at his command were those of Rome’s allies, including Rhodes and Marseilles. The zigzaging of this voyage – whether caused by unfavourable winds or the pursuit of pirates – apparently did nothing to undermine the idea that the Mediterranean ran in a more or less straight line, north of a more or less straight north African coastline. The most important cartographic meridian in ancient mapping [36°] ran through the straits of Gibraltar to the Gulf of Issus, and these two are as near as matters on the same latitude. But in between these Mediterannean extremes the ancient line ran north of the North African coast, whereas it should cut it; it cut Sardinia, whereas it should run well south of that island; and it cut Cape Tainaron on the Peloponnese, whereas that Cape lies over 100 miles north of the 36th parallel. Errors like these had the effect of straightening out the Inner Sea.

FIGURE 1 THE ANCIENT MEDITERRANEAN ACCORDING TO ANCIENT MAPMAKERS to follow.

Poseidonios adopted from Seleucus (one of the astronomers who agreed with Aristarchus) and further developed a theory on the tides which involved the movement of the moon and the sun⁴⁹; whether it was Seleucus or Poseidonios who explained the temporal correlation in terms of astral forces is not clear, but Poseidonios seems more likely. The idea that the tides were somehow tied to the moon perhaps prompted, or was prompted by, his belief in astrology, to which he ‘seems to have been addicted’ in Clagett’s words⁵⁰. The link is expressed clearly in Ptolemy’s bible of astrology, the Tetrabiblos 1.2.1-3, from which I excerpt (Robbins trans. Loeb): ‘The moon, as the heavenly body nearest the earth, bestows her effluence most abundantly upon mundane things, for most of them, animate or inanimate, are sympathetic to her and change in company with her; the rivers increase and diminish their streams with her light, the seas turn their own tides with her rising and setting, and plants and animals in whole or in some part wax and wane with her’. Pliny reports an explanation of why the tides sometimes lag behind the sun and moon’s movement, to wit that optical images travel across space faster than the tidal influence (NH 2.99.216). By Vegetius’ time the theory was taken for granted, but the difficulty of relating the moon’s position to tidal behaviour in any particular place prompted him to give very practical advice: ‘he who is going to fight a naval battle ought to find out the characteristics of the sea and locality before any encounter’ (4.42). Today, much the same situation prevails because of the highly complex relationship between the moon, the earth, and the oceans. It is a commonplace that the moon’s gravitational pull ‘causes’ the tides, but anyone putting to sea consults tide tables or listens to radio broadcasts on tide times – they do not attempt to compute tidal positions and flows by watching the moon.

Poseidonios was also interested in the substance of the earth. He studied the Roman mines in Spain (Strabo 3.2.9, 13.1.67) possibly also the copper mines on Cyprus (3.4.15), the asphalt ‘mines’ at Nymphaeum near Apollonia, at Pierian Seleucia (on the border of Cilicia and Syria) and on Rhodes (7.5.8), and a naptha spring in Babylonia⁵¹ (16.1.15). For those interested in the nature of the ground beneath our feet, mines offered a sort of peephole into the innards of the earth. Seneca (NQ 5.15.1) reports from Asklepiodotus (a student of Poseidonios) that men sent into old mines by Philip II of Macedon saw deep underground ‘huge rivers and vast reservoirs of still water, equal to ours above ground and … with a vast free space overhead’. Just how much they could see with their flame torches is anyone’s guess. Seneca adds (5.15.4) that others ‘dared to descend to a place where they found a strange order of things, layers of earth hanging overhead, dead winds in the darkness, dreadful springs of water flowing for no man, and a night other than our own, and perpetual. Then, after doing these things, they fear the Underworld!’ he adds mockingly.

Strabo (6.2.11 C277) preserves Poseidonios’ record of a new island formed by volcanic activity in the Lipari Isles (between Italy and Sicily), in 126 BC. Seneca summarises Poseidonius’ account of the formation of a new volcanic island in the Aegean (NQ 2.26.4-6), and refers to another which rose in his own time⁵². Justin (Epitome of Trogus’ Philippic History 30.4.1-4) tells of the sudden formation of a new island between Thera and Therasia around 200 BC, and Pliny lists newly formed volcanic islands in NH 2.202. As land could be raised out of sea, and could sink into the sea, Poseidonios thought it possible that the Atlantis story could have a basis in fact (Strabo 2.3.6, 297-303). There are a number of references in Strabo concerning the idea that the sea-beds might rise and fall⁵³.

That data was not entirely qualitative by this time is indicated by another fragment of Poseidonios’ writings which are preserved by Strabo (1.3.9), that the greatest depth of sea that had been measured was over 1000 fathoms (in the Sardinian Sea). Oppian (Hal. 1.9-12) refers to anonymous fishermen who ‘by their techne have mapped out the measures (metra) of the sea’. The technology in question was probably a sounding line, weighted and knotted at regular intervals. When another new Aegean island was formed by volcanic activity in AD 46, Asklepiodotus said that the sea at that point had been 200 feet deep (Seneca NQ 2.26.6). No man has reached or measured the greatest depths of the sea, says Oppian, but ‘down to three hundred fathoms (orguia) men have explored and more or less know the deep’ (1.82-5). The three here is symbolic (meaning ‘lots’) or Oppian is exaggerating widely: 300 orguia is about 1,800 feet. 300 feet would have been an achievement for ancient divers⁵⁴.

Aristophanes’ Clouds takes meteorological phenomena as its springboard and symbol of philosophical studies. The water cycle was well worked out, and early⁵⁵. Ancient weather-lore consisted largely of correlations between types of weather and other phenomena. In the case of astronomical phenomenon, the weather could be compared with centuries-long folk-lore or written records of observations (parapegmata), the latter originating in Babylonian omen literature and made by the Greeks from Meton’s times⁵⁶. The Hippocratics believed weather was a factor in disease, and so they enquired into and frequently noted what the weather had been like just before the onset of ill-health in the patient⁵⁷. In the case of corresponding animal behaviour, such as ants moving their ‘eggs’⁵⁸ (pupae in fact), or tiny spiders spinning single threads by which they float in the air⁵⁹, we seem to be still in the realm of folk-lore or common beliefs, comparable with modern weather-forecasting lore such as if cows sit down it’s going to rain. Aristotle and others attempted to explain correlations between the weather and astronomical phenomena (with or without astrological elements), but this remains an inexact science, modern theories and technology notwithstanding.

4     Mathematical geography

Astronomical observations from near and far enabled the mathematically able to compute the size and shape of the earth, make maps with different projections, and locate on them significant cities or rivers. Our word climate derives from Greek klima (pl. klimata), which literally means inclination, and originally meant a line on the globe of the earth, parallel to the equator, on which the length of the longest day was the same, e.g. 14 hours 30 minutes at Rhodes and at everywhere on the same klima. These lines were drawn at regular arithmetical intervals, usually half-hourly, from 13 hours at Meroe in Ethiopia to 16 hours at Borysthenes on the north coast of the Euxine. In application to geography, klima came to signify also a band or zone around the earth, and it is from this secondary development that our word climate derives.

After mapping the heavens and writing the Almagest Ptolemy took it upon himself to make a more accurate map of the earth than had hitherto existed. Apart from new knowledge gained by the expansion of empire and trade links, there was now available more astronomical data than hitherto, and it was only on the basis of such data that accurate maps could be drawn. This is not to say that there was much such data, but there was some. His finished work gives a spurious air of accuracy, however, because he decided to present all the material to hand – and not just the carefully observed data – in a digital fashion. For example, when told that the journey from X to Y took ‘10 or 12 days’ to cover, Ptolemy translated this into degrees of latitude or longitude via a thumb-rule of average number of stadia covered per day, and made other adjustments which in general seem to arise primarily from a desire to simplify the computations. So the tables of locations set out in his Geography look precise and scientific, but the vast majority of the numbers therein are essentially guesstimates. Ptolemy does not hide this fact: though he is not as explicit on his methodology as we might like him to be, he cautions the reader in book 1.1-6 on the quality of the data he has had to work with. It should also be noted that lists of numbers are peculiarily liable to error in the transmission of the manuscript down through history: try copying out a page of telephone numbers. So some of the errors we find in Ptolemy’s Geography probably entered the text in the course of copying, but it is usually impossible to know which. The digital presentation was not merely for show. The aim of the work is to provide the reader with everything he or she needs to know to be able to make their own maps, emphasising their own part of the world, at their own preferred scale and projection. The digital reference system for locations was, in this context, vastly superior to the descriptive type which preceeded it. By contrast, if ten different people tried to draw a map from, say, Strabo’s Geography, there would probably be ten quite different maps as a result.

5     Maps and politics

Maps were available early and, apparently, were not rarities. Aristagoras (regretably for him) brought a map of the Persian empire to Kleomenes (Herodotos 5.49-50); the founder of a new colony drew up a map of the area marking the allotments to polis, gods and individual settlers⁶³; the map in Aristophanes’ thinking-shop showed Sparta uncomfortably close to Athens (Clouds 200sqq.); visitors to the Lyceum after the death of Theophrastos could study maps of the world painted on wooden panels (DL 5.51); Strabo (1.1.21 C13) expects his audience to have seen a model globe showing the celestial sphere with great circles, ecliptic and so on⁶⁴; even the Roman man-in-the-street was exposed to a map of the world in the portico of Octavia on the Via Lata. The Romans also produced Peutinger-style ‘road maps’, which gave distances in Roman miles between places en route⁶⁵. Terrestrial and celestial spheres were depicted on coins from the C1 BC on⁶⁶. As Field points out, given the small size and few details on numismatic images, ‘viewers are presumably expected to recognize the object from rather slender clues’ (idem). I would point out that this indicates their familiarity. Terrestrial spheres perhaps were less popular and less common than celestial spheres because they revealed unequivocally how little of the earth’s surface was known and still less inhabited⁶⁷. This did however help Seneca make his point about the inconsequentiality of human life and material possessions, when conducting his thought-experiment of the view of earth from space: ‘As the mind wanders among the stars it delights in laughing at the mosaic floors of the rich and at the whole earth with all its gold…the mind cannot despise colonnades, panelled ceilings gleaming with ivory, trimmed shrubbery, and streams made to approach mansions, until it goes around the entire universe and looking down on earth from above (an earth limited and covered mostly by sea – while even the part out of the sea is squalid or parched or frozen) says to itself ‘Is this that pinpoint which is divided by sword and fire among so many nations? How ridiculous are the boundaries of mortals!’…that is a mere pinpoint on which you navigate, on which you wage war, on which you arrange tiny kingdoms – tiny, even though ocean does run to meet it on both sides’ and so on (NQ 1 Pref. 7-11).

Besides these cultural aspects there are practical ones. Mapping onto a globe is straightforward. But any map which tries to project a three-dimensional object, the earth, onto a two-dimensional surface, a sheet of papyrus, block of stone, or computer screen, distorts it: stretching, squeezing, cutting, or twisting parts of it. It is not possible to show accurately on the same map more than one thing – distances, or areas, or directions, or shapes. So the mapmaker has to choose which property to prioritize, and around which point or line, and distort the rest as necessary, or chose to project an image which is inaccurate in all respects but which minimizes the distortion in all.

What is remarkable about the best ancient mapmakers is not their errors, which follow the usual pattern of ethnocentricity, exaggeration close to home, and progressive omission and underestimation as they move further from their known world into the unknown, but their self-consciousness of such ‘human error’, and their desire to overcome it by using astronomical data to locate places and size regions accurately and without prejudice. Their problem then was the rarity of such data (the latitudes of only Alexandria, Marseilles, Rhodes, Rome, Syene and few others were astronomically determined). Ptolemy, moreover, appreciated the distortion created by a projection.

The awareness of human error in geography extended beyond the difficulties of accurate mapping to the difficulties of obtaining accurate information of any sort. As Plutarch noted in his introduction to his Life of Theseus (Perrin trans.), ‘Just as geographers, O Socius Senecio, crowd on to the outer edges of their maps the parts of the earth which elude their knowledge, with explanatory notes that ‘What lies beyond is sandy desert without water and full of wild beasts’, or ‘blind marsh’, or ‘Scythian cold’, or ‘frozen sea’, so in the writing of my Parallel Lives, now that I have traversed those periods of time which are accessible to probable reasoning and which afford basis for a history dealing with facts, I might well say of the earlier periods: ‘What lies beyond is full of marvels and unreality, the land of poets and fabulists, of doubt and obscurity’’.

Notes

1. Strabo 2.2.1. See Heiberg 1922 p. 79. Strabo also criticizes Poseidonios for being too ‘physical’ (e.g. 1.3.12) and theoretical in the Aristotelian mould (e.g. 2.3.8).

2. For example, following a discussion of optical illusions and atmospheric phenomena, he tells the story of Hostius Quadra’s mirrored bedroom and what perverted things went on there, NQ 1.16; in 3.17-18 he describes the slow death of a fish (a red mullet) on a diner’s plate; in 4A pref.17 Caligula’s tortures and brutality; in 6.1-2 numerous ways to die from natural causes; and in 7.31 self-castration, among other things.

3. Such scenes in ancient literature are usually assumed to have been included for their moralizing role (though that is not the usual explanation for such scenes in modern films), but that hardly explains the precise form that they take.

4. The latter association probably arose because most epicentres were underwater, causing tsunami; for an ancient explanation of the association see Seneca NQ 6.23.4.

5. Seneca has received quite a lot of attention in the last two decades, although much more of it is concerned with his literary works (tragedies, letters and the like) or with the difference between the morals he professes and his actual behaviour, than with his Natural Questions. Rosenmeyer 1989 has attempted to link the two areas of Seneca’s activity. For an introduction to Stoicism see Sandbach 1975 or Sharples 1996.

6. There is full discussion of this map in Dilke 1985 pp.41-53.

7. This obviously relates to governors who were not born into the area they govern, as appropriate for the Roman empire.

8. Strabo’s view on the unproftability of invading Britain is interesting in this regard; 2.5.8 C115 end-C116. Meeting the needs of state is also illustrated by Arrian’s Periplous of the Euxine (voyage round the Black Sea) which is written in the form of a letter to the emperor Hadrian; Arrian was legate of Cappadocia, probably when he researched if not wrote it. The same Arrian wrote the best ancient history of the expedition of Alexander the Great (the Anabasis), a description of India (the Indika) and a handbook on military tactics (the Tekhne Taktika), amongst other things.

9. See Sheikh ‘Ibada al-Nubi 1997.

10. See Rihll 1993.

11. Conveniently (and translated) in Schoff ed. Isidore of Charax Parthian Stations p. 42.

12. History of ancient geography, Preface p. xi, emphasis added.

13. For example, it is only since the eruption of Mount St Helens (1980) that we have finally understood the type of eruption which corresponds with and explains the ancient descriptions of Vesuvius’ catastrophic eruption and the archaeological evidence of Pompeii and Herculaneum.

14. Except, of course, for a brief mention of Eratosthenes’ calculation of the circumference of the earth, raised, of course, in the context of astronomy, p. 98, mentioned again on p. 144. Lindberg does say that Capella failed to understand Eratosthenes’ method, but he does not indicate that Capella is not even consistent: his character Geometry gives a figure of 252,000 stades (596), whilst later Astronomy says (858) that Geometry had said 406,010 stades! For an assessment of Capella see Stahl 1971.

15. 1996; this volume of papers by diverse hands is devoted to environment and culture.

16. There is a good discussion of these, with extracts in English translation, in Dilke 1985 chapter 9.

17. The text and testimonia concerning Pytheas has been edited and translated by Roseman 1994.

18. Indeed, this observation needed more effort to believe: Herodotos didn’t.

19. As Rusten notes in the new Loeb edition (1992), this section (along with sections 6-10) seems to have been misplaced during transmission of the text, and to belong not to the obsequious character but to some other such as the man of petty ambition, on which see continuation of the main text.

20. See Strabo 1.2.6, naming Kadmos and Pherekydes with Hekataios as early prose writers. Pliny NH 7.205 and Suda s.v. ferekudhV name only the first two, but the latter contradicts himself and names Hekataios with Pherekydes s.v. ‘EkataioV ‘Hghsandrou.

Further Reading

E H Bunbury’s History of ancient geography 2 vols (London, 1879, reprinted Amsterdam, 1979) is still a good place to start for a comprehensive survey of the subject. J O Thomson’s History of ancient geography (Cambridge, 1948) also provides an overview. O A W Dilke’s The Roman Land Surveyors: an Introduction to the Agrimensores (Newton Abbot, 1971), and Greek and Roman Maps (London, 1985) contain much more than their titles suggest. A new introduction to ancient geography by K Brodersen and a study on ancient meteorology by L Taub are soon to be published, both by Routledge.

Principal primary sources in English translation:

Anon. Periplus of the Erythraean Sea trans. Schoff (New York 1912, also by Huntingford, Hakluyt Soc., 1980)

Anon. Aetna is in the Minor Latin Poets volume, ed. and trans. J W and A M Duff, Loeb, 1935.

Aristotle Meteorology ed. and trans. H D P Lee, Loeb, 1952.

Posidonius' fragments have now been translated by I G Kidd, Cambridge 1999.

Ptolemy Geography see now the annotated trans of the theoretical chapters [i.e. 1, 2, 7 and 8] by J L Berggren & A Jones, Princeton Up, Oxford, 2000, which includes a good introduction putting the work in context. [The trans. of E Stevenson (Mineola, 1991) is unreliable.]

Pytheas On the Ocean ed. and trans. C Roseman (Chicago, 1994).

Theophrastos On weather-signs in Loeb Enquiry into Plants vol 2; On Stones text, trans and comm by Caley & Richards (Ohio UP, 1956), also by Eichholz (Oxford, 1965)

Strabo Geography English trans. by H Jones, 8 vols., Loeb, London, 1917-32; vol. 1 reprinted in 1989.

For the Corpus Agrimensorum Romanorum see now J.B. Campbell, The Writings of the Roman Land-Surveyors (London, 2000).

A selection was translated into English by Cary & Warmington in The ancient explorers in 1929, and by Warmington Greek geography in 1934. A different sort of text altogether was provided by Rhys Carpenter in Beyond the pillars of Hercules 1966, a reconstruction of some ancient voyages, with many fragmentary sources in translation, and a few in toto.           Home

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Last modified: 11 April 2007