Eratosthenes and the History of GeographyThe BackgroundThe discipline of geography began with Eratosthenes of Kyrene and the publication of his Geographika in the last third of the third century BC. Before that time there had been interest in the surface of the earth, its formative processes, and its shape and structure, but it was Eratosthe-nes who brought these divergent streams of thought and experience together to create a new scholarly discipline. He also devised the ter-minology to accompany his ideas, with the new words “geography” (gvgra ´a) and “geographer” (gvgra´o), based on the verb gvgra´v, “to write [about] the earth.” 1 Eratosthenes’ treatise was titled Gvgra a´ (Geographika),2 and the word “geography” was probably created by analogy with terms such as gvmtr´v, “to measure [or survey] land,” which itself had evolved from a technique, as Herodotos saw it, to a scholarly discipline.3 In writing his treatise Eratosthenes built on a l These terms appear in extant Greek literature in the Geography of Strabo (1.1.1, 16), from the Augustan period, but it is clear that they originated two centuries earlier with Eratosthenes, whom Strabo was quoting. The earliest extant citation of the word gvgra ´a is by Philodemos of Gadara (On Poetry 5.5), who lived from about 110 to 40 BC and was in Italy after the 70s (Tiziano Dorandi, “Philodemus,” BNP 11  68–73). The text is fragmentary, although it is clear that Philodemos was arguing against the belief that poets needed scholarly knowledge, listing as unnecessary disci-plines music, seamanship, and geometry, as well as geography. It is not clear whom Philodemos was arguing against: the previous citation preserved is Herakleides of Pon-tos, the scholar of the fourth century BC, who seems too early to have used the word “geography,” and it is probable that a more recent source is missing.2 This seems the most probable title (see Strabo 2.1.1). Also used are Gvgra ´a (Geography), at Strabo 2.1.41, which seems less likely, and Gvgraoy´mna, a variant of Gvgra ´a that appears only in scholia (F117, 145). See Berger 17; Fraser, PA vol. 2, p. 756.3 Herodotos 2.109; Plato, Theaitetos 17 (162e). An older word, osmogra ´h, “describ-ing the world,” was apparently the title of a work by Demokritos of Abdera (Diogenes Laertios 9.46), who wrote a geographical treatise about which nothing is known (Strabo 1.1.1). Despite its origins in the ﬁfth century BC, this word did not remain in favor,
tradition of interest in the surface of the earth and its landforms and in-habitants that went back to the beginning of Greek intellectualism. He called Homer the ﬁrst geographer (F1), a casual application of the tech-nical vocabulary of the new discipline, but also recognition of Homer’s role in early understanding of the inhabited earth. Homer’s world was astonishingly broad, with vague knowledge of the mountains of central Europe, the peoples north of the Black Sea, and the upper Nile and pygmy tribes. There are hints of the climatic realities of the far north, where the Kimmerians never see the sun, but much less knowledge of the west, with nothing beyond Sicily, and no sense of any overall concept of the earth or its surface.4When Greeks began to spread into the western Mediterranean in the latter eighth century BC, they learned about these regions as well as the overall shape of the sea and its single, western outlet. About 630 BC one Kolaios of Samos became the ﬁrst Greek to go out into the Atlantic and to gain access to the wealthy mineral resources of the southwestern Iberian Peninsula.5 Although this was encroaching on Carthaginian territory, both wealth and topographical data ﬂowed back into the eastern Mediterranean. To the south, the establishment of Kyrene at about the same time provided some knowledge about interior Africa, as the city soon became an outlet for far-ranging trade, the north end of routes that originated south of the Sahara.6 Interest in circum-navigating Africa and connecting the lands south of the Red Sea to those beyond the Pillars of Herakles resulted in a number of expeditions, the ﬁrst at the time of the pharaoh Necho II (610–595 BC). Phoenicians, Carthaginians, and even Persians made the attempt.7 Also in the sev-enth century BC Greeks settled the Black Sea and became more aware of the rivers and peoples to its north. To the east the various great em-pires could provide information, especially after the rise of Persia in the to be replaced by geographia, which has essentially the same meaning: Eratosthenes probably wanted new terminology for his new ways of thinking. Diogenes Laertios’ use (9.48) of the title Geographia for a treatise by Demokritos is anachronistic, perhaps an adjustment of his title Kosmographia.4 For a discussion of Homeric geography and its numerous toponyms, see J. Oliver Thomson, History of Ancient Geography (Cambridge 1948) 19–27; Germaine Aujac, Éra-tosthène de Cyrène: Le pionnier de géographie (Paris 2001) 19–22. A collection of trans-lated texts of early geographical writers appears in George Kish, A Source Book in Ge-ography (Cambridge, Mass. 1978) 9–72.5 Herodotos 4.152.6 Herodotos 2.32–3.7 Herodotos 4.42–3; Roller, Pillars 23–6.
THE BACKGROUND 3sixth century BC. Cyrus the Great had gone to his death among the Massagetai, east of the Caspian Sea, in 529 BC, and about 15 years later Dareios I commissioned a certain Skylax of Karyanda to sail down the Indos and to return to the Red Sea. His published report was probably the earliest Greek travel account: it survived to be used by Herodotos.8By 500 BC all the topographical and ethnographic information re-sulting from the expansion of the Greek horizon was beginning to ﬁnd literary expression. Soon after Skylax, perhaps by 500 BC, the term logogra´o (“writer of stories”) was applied to those who used the new medium of prose to record city histories, ethnographies, and topographi-cal data.9 Among the several who are known, the most signiﬁcant is Hekataios of Miletos, a prominent political leader in his own city around 500 BC, who wrote a Circuit of the Earth in two books, which included a discussion of Europe and Asia: he was probably the ﬁrst to see the world in terms of continents.10 His toponymic range was amazingly wide-spread: well into the Iberian Peninsula, Keltic territory, Skythia, the Kaukasos and beyond, India, and Ethiopia.11 The extant fragments are mostly toponyms, so it cannot easily be determined how much ethnog-raphy and geography were included, yet many of his ideas matured and became more accessible in the Histories of Herodotos, written half a century later.Hekataios also made use of a recent technique that would become inseparably connected with the discipline of geography. This was map-making, said to have been an invention of Anaximandros of Miletos, an important ﬁgure in both the theoretical and practical origins of geogra-phy. He was an associate or disciple of his famous compatriot Thales, the originator of Greek intellectual thought, which places Anaximan-dros in the ﬁrst half of the sixth century BC. Signiﬁcant in the develop-ment of Greek natural science and cosmology, he is of interest in the history of geography not only as the ﬁrst mapmaker but also as the ﬁrst 8 Herodotos 4.44. The surviving text under the name of Skylax is actually an ac-count from the fourth century BC, and not the work of the sixth-century explorer.9 Thoukydides 1.21; see also Aristotle, Rhetoric 184.108.40.206 The large number of topographical entries from Hekataios (over 300) in the Eth-nika of Stephanos of Byzantion are deﬁned as “Hekataios in his Europe” or “Asia” (FGrHist #1), although one must be cautious about the late derivative source, since Stephanos probably did not realize that Hekataios believed in only two continents (see Lionel Pearson, Early Ionian Historians [Oxford 1939] 31, 62–6). By early in the ﬁfth century BC, the theory of continents was well established (Pindar, Pythian 9.8; Aischy-los, Persians 718).11 Hekataios (FGrHist #1) F45–58, 184–93, 296–9, 325–8.
to conceive of the shape of the earth, although, as is generally the case with early Ionian Greek thought, the sources are elusive. Herodotos did not mention Anaximandros by name but referred several times to maps, derisively complaining about the inaccuracies of those of his own day and recounting the tale of how the Spartans were unexpectedly con-vinced not to give aid to the Ionian Revolt, because a map shown to them by Aristagoras of Miletos demonstrated how far away Persia was. Herodotos also provided a source for creating such a map, since in his Histories this incident is followed immediately by a precise itinerary of the Royal Road from Sardis to Sousa, complete with distances, stopping points, and a few topographical features, a digression that intrudes into the account of the career of Aristagoras.12 These comments by Herodo-tos are the earliest extant discussions of maps. Later authors, including Eratosthenes himself (F12), speciﬁcally associated Anaximandros with the origins of mapmaking.13 Thus the technique originated in Miletos during the sixth century BC: by the following century Herodotos, the ﬁrst to realize that maps could mislead as well as inform, offered his critique and complained that they tended to over-regularize the surface of the earth. Yet mapmaking was ﬁrmly established as one of the essen-tial tools for the emergent discipline of geography.14 By providing a vi-sual overview, maps also made it possible to relate distant portions of the world to one another, a strikingly new way of looking at the earth. Herodotos, probably using data from Hekataios, was able to suggest that Egypt, Kilikia, Sinope, and the mouth of the Istros lay on the same line,15 which, although a crude calculation (the mouth of the Istros is over 500 km. west of the longitude of Sinope), is the ﬁrst attempt to cre-ate a meridian. He did not have a speciﬁc term for this concept but merely stated that places “lie opposite” (aÉnt ´h ´ta ) to one another, a term probably long understood by seamen to connect points on opposite sides of the Mediterranean. Yet this sense of “lying opposite” survived, and Eratosthenes was to use the concept for places that were far apart but on the same latitude or longitude.16 The Greek word for midday, 12 Herodotos 4.42, 5.49–54.13 The word for map seems originally to have been p ´na (Strabo 1.1.11, quoting Er-atosthenes, F12), a “plank” or “drawing board” (Homer, Odyssey 12.67; Iliad 6.169). Dio-genes Laertios (2.2) used pr ´mtron (originally “circumference” [Herodotos 1.185] but having the sense of “outline”) for Anaximandros’ creation, speciﬁcally noting that it was “of the land and sea.”14 O.A.W. Dilke, Greek and Roman Maps (Ithaca 1985) 22–31.15 Herodotos 2.34.16 For example, southern India and Meroë (F50).
THE BACKGROUND 5mshmbr ´a, became the term for a geographical meridian, since when it was noon at a given place, every other point where it was also noon was on the same meridian.17Anaximandros’ other great contribution to geography was his theori-zation about the very shape of the earth itself. Building on Thales’ view of a world ﬂoating on the water that was the basic component of the cos-mos,18 Anaximandros believed that the earth was shaped like a column (presumably the surface of a drum), perhaps reﬂecting the monumental stone architecture that was beginning to spread through the Greek world in his day.19 Although his concept was soon abandoned, it marks the ﬁrst systematic attempt to explain the overall shape and form of the earth, which, like mapmaking, would become an essential part of the discipline of geography. Yet the concept of the earth as a disk or column drum had apparent ﬂaws, especially as seamanship revealed both the curved sur-face of the earth and the visible changes in celestial phenomena as one went north or south. Although there were inventive attempts to explain these pieces of information within the concept of an earth-disk,20 before long thoughts turned toward conceiving of the earth as a sphere. This seems a Pythagorean idea,21 connected with the harmonic and mathe-matical perfection of the cosmos and the sphere.22 Parmenides of Elea, active in the ﬁfth century BC, is also said to have tinkered with the con-cept, and perhaps was the ﬁrst to divide the earth into climate zones.23 It is with Plato that there is the ﬁrst extant and extensive description of this new perspective of the world, as well as another important idea, that its inhabited part was only a small portion of the entire earth.2417 Aristotle, Meteorologika 2.5 (with textual issues), 3.5.18 Aristotle, On the Heavens 2.13.19 Duane W. Roller, “Columns in Stone: Anaximandros’ Conception of the World,” AntCl 58 (1989) 185–9.20 Anaximenes of Miletos, the traditional successor to Anaximandros, suggested that the northern parts of the earth were higher and thus caused the sun to disappear (Aristotle, Meteorologika 2.1).21 This is not the place to discuss the complex distinctions between Pythagoras, the emigrant from Samos who established himself at Kroton around 530 BC, and Pythago-reanism, which as early as the time of Aristotle (Metaphysics 1.5.1; On the Heavens 2.13) was recognized as an intellectual movement separate from the historical personality.22 The sources are summarized in William Arthur Heidel, The Frame of the Ancient Greek Maps (New York 1937) 63–80.23 Diogenes Laertios 9.21–2; Strabo 220.127.116.11 Plato, Phaidon 109b–110a. The Pythagoreans may have been the ﬁrst to suggest that there were other continents beyond those surrounding the Mediterranean (Dio-genes Laertios 8.25–6).
Many of these ideas were formalized in the work of Plato’s associate the mathematician Eudoxos of Knidos. In his Circuit of the Earth25 he put forth the idea that the inhabited part of the earth was much longer east-west than north-south, which led to the natural conclusion that India could be reached by sailing west from the Pillars of Herakles.26 He may also have been the ﬁrst to estimate the circumference of the earth,27 and divided its surface into latitudinal zones, probably using the word that Eratosthenes was later to adopt, l ´ma, originally meaning “slope.” 28 Eudoxos does not seem to have carried the idea of klimata far, but it laid the groundwork for Eratosthenes’ more precise conceptualization.By the mid-fourth century BC, the accumulation of knowledge made it possible for Ephoros of Kyme to include world geography as a major section of his history, published shortly after 340 BC. In this treatise he divided the world into four ethnic sections and provided more informa-tion on the north than previously available, and also discussed scientiﬁc issues such as the tides.29 Although the word “geography” was probably still not yet in use, Ephoros moved closer than anyone previously to cre-ating an actual scholarly discipline.The proliferation of topographical and ethnographic knowledge be-cause of the travels of Alexander is well known. This expansion of hori-zons created a large amount of data, especially about the remote east-ern parts of the world, which was made accessible by the published reports of those with him, many of which were used as primary sources by Eratosthenes. Although the focus of the era and successive genera-tions was toward the east, the west was also more intensively explored: Pytheas of Massalia traveled to the British Isles and reached the Arctic and Baltic in the 320s BC,30 and an unknown traveler went down the West African coast perhaps as far as the Senegal River sometime be-tween 361 and 335 BC.31Despite the sudden increase in topographical data, theoretical spec-ulation was not neglected. Aristotle’s thoughts on geography are little 25 Agathemeros 1.2; Plutarch, On Isis and Osiris 6; Thomson (supra n. 4) 117–18.26 Aristotle, Meteorologika 2.5, On the Heavens 2.14.27 He may be the source for Aristotle’s unattributed ﬁgure of 400,000 stadia (On the Heavens 2.14); Thomson (supra n. 4) 116.28 Strabo 9.1.1–2; Polybios 2.16.3, 7.6.1. Although the extant use of the word is no earlier than the second century BC, it is clear from Polybios and Strabo that it had an earlier ancestry. See Karlhaus Abel, “Zone,” RE Supp. 14 (1974) 989–1052.29 Ephoros (FGrHist #70), F30a, 131–4.30 Roller, Pillars 57–91.31 Pseudo-Skylax 112.
known, but he provided the ﬁrst extant ﬁgure for the circumference of the earth (400,000 stadia) and suggested that one could reach India by sailing west from the Pillars of Herakles.32 He was also crucial in pre-serving and synthesizing the ideas of his predecessors, and his Meteo-rologika contains a certain amount of geographical material, but no title survives that seems to indicate a purely geographical treatise.33 Yet his students and immediate successors, the last generations before Eratos-thenes, were active in the discipline. Dikaiarchos of Messana wrote a geographical treatise, perhaps titled Circuit of the Earth, and created the main terrestrial parallel, making the east-west length of the inhab-ited world one and one-half times the north-south.34 He also may have been responsible for calculating the circumference of the earth at 300,000 stadia and further reﬁning the terrestrial zones.35 He was the ﬁrst to make use of the information from the Arctic supplied by Pytheas, which far expanded the geographical extent of observed data. Another member of the Aristotelian school, Straton of Lampsakos, examined questions about the formation of the seas.36 With the theories of Di-kaiarchos and Straton, the study of the earth had reached the point where Eratosthenes was able to pull all former thought together and use his own original mind to create the discipline of geography.The Life of EratosthenesAlthough biographical data about Eratosthenes are limited, it is possi-ble to reconstruct a broad outline of his career.37 He was the son of Aglaos 32 Aristotle, On the Heavens 2.14. On Aristotle’s geography, see Germaine Aujac, “Les modes de representation du monde habité d’Aristote a Ptolémée,” AFM 16 (1983) 14–19.33 Paul Moraux, Les listes anciennes des ouvrages d’Aristote (Louvain 1954). Geo-graphical data may have appeared in other works, such as the Governments of 158 Cit-ies and On the Rising of the Nile (perhaps actually a work of Theophrastos: see Moraux, pp. 253–4).34 Dikaiarchos F122; Paul T. Keyser, “The Geographical Work of Dikaiarchos,” in Di-caearchus of Messana (ed. William W. Fortenbaugh and Eckhart Schütrumpf, Rutgers University Studies in Classical Humanities 10, New Brunswick 2001) 363–5.35 Kleomedes 1.5; Fraser, PA vol. 2, p. 598; Thomson (supra n. 4) 154.36 For Straton, infra, pp. 130–1.37 For the major ancient sources see infra, pp. 268–70. The best modern sources are Fraser, PBA 175–207; Fraser, PA vol. 1, pp. 525–34; G. Knaack, “Eratosthenes” (#4), RE 6 (1907) 358–88; D. R. Dicks, “Eratosthenes, DSB 4 (1971) 388–93; Jerker Blomqvist, “Al-exandrian Science: The Case of Eratosthenes,” in Ethnicity in Hellenistic Egypt (ed. Per Bilde, Aarhus 1992) 53–73; Geus, Eratosthenes; Alexander Jones, “Eratosthenes of Kurene,” in The Encyclopedia of Ancient Natural Scientists (ed. Paul T. Keyser and THE LIFE OF ERATOSTHENES 7
and was born in the mid-280s BC in Kyrene. Both his name and that of his father are rare, indicating humble origins and demonstrative of the upward mobility possible in the Hellenistic world.38 Kyrene, founded by Greeks in the seventh century BC, had long existed as a prosperous and cosmopolitan outpost of Greek culture, lying between Egyptian and Car-thaginian territory, and serving as the contact point between the Greek world and interior Africa.39 The city controlled a vast territory, perhaps more than any Classical Greek state. It had a rich economy, based largely on the export of horses and silphium. Libyans had long been known to the Greeks for their excellent horsemanship,40 and the exotic herb silphium (s ´l on, ferula tingitana), almost mystical in its reputa-tion, had been exported to mainland Greece as early as the time of Solon and had a wide variety of culinary and medicinal uses.41 Kyrene was full of distinctive art and architecture and had a ﬂourishing intellectual tradition: in the ﬁfth century BC the engaging personality Aristippos had come to Athens to study with Sokrates, and, with his daughter Arete and her son Aristippos, developed the Kyrenaian school of thought.42 Like most Greek states, the history of Kyrene is one of political instabil-ity, with the city eventually coming under sporadic Persian control and then that of Alexander the Great. Upon Alexander’s death Ptolemaios I provided a new constitution, although there continued to be occasional revolts and independent periods. It was into this environment that Era-tosthenes was born during the last years of Ptolemaios I.43By the late 260s BC Eratosthenes had gone to Athens for study. He was impressed with the vigorous intellectual environment of the city, and mentioned among his teachers Ariston of Chios, Arkesilaos of Pi-tane, who had recently become director of the Academy, and Bion of Georgia L. Irby-Massie, London 2008) 299–302. For sources that focus on Eratosthenes as a geographer, see infra, pp. 32–5.38 Blomqvist (supra n. 37) 58–60.39 A.H.M. Jones, The Cities of the Eastern Roman Provinces (Oxford 1937) 351–60.40 Pindar, Pythian 9.4; Sophokles, Elektra 727; Herodotos 4.170, 189.41 Solon F39; Theophrastos, Research on Plants 6.3; Andrew Dalby, Food in the An-cient World from A to Z (London 2003) 303–4.42 Strabo 17.3.22; Diogenes Laertios 2.65–86.43 The Souda date of Ol. 126 (276–3 BC) seems too late to assume any study with Zenon of Kition (see Strabo 1.2.2), who died around 260 BC: Ol. 124 or 125, each requir-ing the change of only a single letter, seems better (Fraser, PBA 175–6). Eratosthenes’ lifetime falls within narrow limits: he must have been old enough to have studied with Zenon, and he must have survived the death of Arsinoë III in 204 BC, dying between the ages of 80 and 82 (Souda; Censorinus, On the Birthday 15.2; Loukianos, Makrobioi 27).
Borysthenes, whose views were eclectic. Other teachers, according to Strabo, included the little-known Apelles of Chios and the founder of Stoicism himself, Zenon of Kition, although any contact would have been brief since he died shortly after Eratosthenes’ arrival.44 Also part of his education would have been the mathematical training at the Academy implicit in his later work. The Souda adds two more teachers, Lysanias of Kyrene, a philologist and grammarian with a Homeric in-terest,45 and Eratosthenes’ compatriot the famous Kallimachos. Whether or not Kallimachos was one of his teachers, Eratosthenes would have had regular contact with the most prominent Kyrenaian intellectual of the previous generation. Their paths would have crossed numerous times, and they evidently had academic disputes.46Eratosthenes’ exposure to the varied philosophical schools of Athens led Strabo to condemn his lack of depth as a philosopher, someone who had learned only enough to see philosophy as an escape (para´bas ). The extensive nature of Eratosthenes’ later scholarly endeavors par-tially supports this view: he was expert, but not the expert, in many things, and thus was called “Beta” (“Second”) or “Pentathlos.” 47 Like so many interdisciplinary scholars from ancient to modern times, he could be assailed from all sides.48 Strabo’s irritation that he did not pay due respect to Zenon further reveals the independence of Eratosthenes’ out-look and endeavors.Thus Eratosthenes’ education emphasized philosophy and, to a lesser extent, mathematics, with perhaps some philological training. Lacking is any evidence for a geographical education, but this is not unexpected given that there was no such discipline. Yet the Greek literature that Er-atosthenes studied was replete with references to far peoples and places. This was especially true of Homer, whom Eratosthenes would come to believe was the ﬁrst geographer. Hekataios’ Circuit of the Earth, with its list of distant places, may still have been available.49 Aischylos, Herodo-tos, and others provided material that would coalesce into the data for geographical scholarship. Half a century before Eratosthenes’ birth, 44 Strabo 1.2.2; Diogenes Laertios 7.1–38, 160–4, 4.28–45, 4.46–57. For Eratosthe-nes’ education see Giorgio Dragoni, “Introduzione allo studio della vita e delle opere di Eratosthene,” Physis 17 (1975) 49–52.45 Athenaios 7.304b, 14.620c.46 F8-9; the dispute is also implied in F2 and 12.47 Souda, “Eratosthenes.”48 Strabo 18.104.22.168 It was certainly extant as late as the mid-fourth century BC: see G. L. Barber, The Historian Ephorus (second edition, Chicago 1993) 118–19.THE LIFE OF ERATOSTHENES 9
Ephoros had been the ﬁrst to write on world geography.50 Eratosthenes’ upbringing in Kyrene exposed him to exotic contacts at one end of the Greek world, and it is especially interesting that one of his teachers, Bion, came from the other end, from far-off Borysthenes, the collective term for the cluster of Milesian settlements at the mouth of the river of the same name (the modern Dneiper) at the north end of the Black Sea, one of the most remote areas of Greek settlement.Eratosthenes also was born into a world of expanding geographical knowledge. It had only been 40 years since the death of Alexander the Great. The environment of the Successors had recently produced works by Androsthenes, Nearchos, Onesikratos, Ptolemaios I, and others re-counting their travels with Alexander. The early Seleukids commis-sioned their own investigations into the far eastern reaches of the known world. The reign of Ptolemaios II (285/3–246 BC) would be one of further exploration, especially up the Nile and into East Africa, creating a new series of published reports. Although formal training in geography was impossible, Eratosthenes’ world overﬂowed with geographical data.After perhaps 20 years studying and writing in Athens, a period for which there are no details, Eratosthenes’ career was dramatically af-fected by changing events in Alexandria. In early 246 BC Ptolemaios II died. Before the end of January, his son Ptolemaios III was proclaimed king, a reign that would last until the winter of 222/1 BC. More distin-guished than the king was his wife Berenike II, from Kyrene. She was the daughter of Magas, who was related to the Ptolemies by marriage and had proclaimed himself king of Kyrene when Ptolemaios II came to the throne, but who decided late in life that a reconciliation with the Ptolemies would be wise, and proposed that his daughter marry the heir-apparent Ptolemaios III. This eventually happened, but not before Berenike killed her mother’s candidate for her husband, the Antigonid prince Demetrios, who had been caught in her mother’s bed. Although legally the Kyrenaika reverted to Ptolemaic control, Berenike contin-ued as virtual queen of her own territory.51The quarter century of rule by Ptolemaios III and Berenike II saw both the maximum political extent of the Ptolemaic empire and the greatest ﬂowering of Alexandria as an intellectual center. The establish-ment of the Library by Ptolemaios I and its stocking from the great col-lections of the day, including, allegedly, those of Euripides, Aristotle, and 50 Supra, p. 6.51 Justin 26.3; Günther Hölbl, A History of the Ptolemaic Empire (tr. Tina Saavedra, London 2001) 45–6.
Theophrastos,52 had created an outstanding intellectual environment that, in terms of formal structure, was unprecedented. Scholars such as Euclid and Aristarchos of Samos were among the ﬁrst to ﬂourish in Al-exandria. The reign of Ptolemaios II saw the arrival of the poets Theokri-tos, Kallimachos, and Apollonios of Rhodes. The most distinguished aca-demic post in Alexandria was that of Librarian, which often carried with it the position of royal tutor.53 The organization of the Library was largely implemented by Theophrastos’ student Demetrios of Phaleron, who brought both political and academic credentials and was available because of the collapse of his political career. Eventually he was caught up in the intrigues of the regime change at the death of Ptolemaios I and was expelled by his successor, dying soon thereafter from the bite of an asp.54 Demetrios was succeeded by Zenodotos of Ephesos, probably the ﬁrst to hold the actual title of Librarian. He was known for his re-cension of early Greek poetical texts, especially Homer.55 He was fol-lowed about a decade later by Apollonios of Rhodes, who lasted into the rule of Ptolemaios III, but who was forced into retirement shortly after the accession of the new king, who summoned Eratosthenes from Ath-ens to be his replacement.56 The role of Kallimachos in this, who seems to have been ill-disposed toward Apollonios and never held the position of Librarian himself, is uncertain. Both Apollonios and Eratosthenes were his protégés, although it is unlikely that Eratosthenes was ever Kallimachos’ formal student,57 yet it appears that the one out of favor was replaced with the one more preferred, who was also a fellow-citizen and whose shorter, more occasional poetry was more appealing than the epic style of Apollonios.58 But the accession of Ptolemaios III and, more importantly, the Kyrenaian queen Berenike, certainly tilted the court 52 Athenaios 1.3.53 The title normally translated as Librarian is Prosta´th, a common Ptolemaic term for the head of an organization. Zenodotos was probably the ﬁrst to hold the ofﬁce: see Fraser, PA vol. 1, pp. 320–335, for the early history of the Library and its organization.54 Diogenes Laertios (5.78) implied that it was an accident, but Cicero in 54 BC (Pro C. Rabirio Postumo Oratio 23, an oration with strong Alexandrian connections) said it was suicide. It is intriguing that this should be yet another case of suicide-by-asp from Ptolemaic Egypt.55 Fraser, PA vol. 1, p. 450–1.56 The sequence of Librarians is preserved in OxyPap 1241.57 Fraser, PA vol. 2, p. 490.58 Fraser, PA vol. 1, pp. 331–2. Nevertheless Eratosthenes and Kallimachos eventu-ally ended up at odds with one another, since Eratosthenes suggested several times in the Geographika (F2, 8, 9, 12) that Kallimachos’ scholarship was deﬁcient.THE LIFE OF ERATOSTHENES 11
toward Kyrene, and the major Kyrenaian intellectual in Alexandria, Kallimachos, would have had a say in the ﬁlling of the position of Li-brarian. Eratosthenes, moving at about the age of 40 into this ﬂourish-ing cultural environment with its Kyrenaian slant, had already gained a reputation as a broad scholar and creative personality. His earliest publications were perhaps on philosophy, such as the treatise Platoni-kos, probably a dialogue, but with certain mathematical ideas that re-ﬂected his own interests rather than any Platonic heritage.59 He was gaining fame, however, not for his philosophical writings, which were somewhat derivative, or his mathematical speculations, but as a poet in the tradition of Kallimachos.60 This certainly played a role in his ap-pointment as Librarian, as did his reputation as a broadly learned scholar, a true philologos,61 as well as his nationality. He commemorated his appointment as Librarian by writing a poem that not only adeptly offered a mathematical proof of how to double the cube but honored the regime, especially the heir-apparent, the future Ptolemaios IV, and that was set up on a votive column in Alexandria.62The early years of Eratosthenes’ tenure seem to have seen an em-phasis on mathematics.63 He became a close associate of Archimedes, who may have visited Alexandria at about this time. He sent unpub-lished material to Eratosthenes for comment, and acknowledged his help with effusive praise in his Method of Mechanical Theorems.64 This would have given Eratosthenes great credibility as a mathematician and prepared him for the treatise that would lead him from mathemat-ics to geography, his On the Measurement of the Earth,65 in which he set forth his method of calculating the circumference of the earth, a feat so profound yet so simple that it remains today one of the most amazing pieces of ancient scholarship, treated as such since antiquity.66 Although 59 See the detailed examination of the treatise by Geus, Eratosthenes 141–94.60 Fraser, PBA 184.61 The word, in its meaning of “a learned person,” probably comes from Athenian or-atory (the earliest extant example is Aristotle, Rhetoric 2.23.11, although oddly applied negatively, about the Lakedaimonians). Eratosthenes was allegedly the ﬁrst to apply it to himself (Suetonius, Grammarians 10).62 Fraser, PBA 185–6.63 In fact he may have been responsible for organizing the mathematical and scien-tiﬁc collections of the Library: see Germaine Aujac, “Ératosthène, premier éditeur de textes scientiﬁques?” Pallas 24 (1977) 3–24.64 Archimedes, On the Method of Mechanical Theorems, Preface (see infra, p. 270).65 For the fragments of the Measurement, see infra, pp. 263–7.66 See, for example, Pliny, Natural History 2.247. Egyptian intellectuals were also impressed, and Elephantine, the island in the Nile at Syene, was represented in hiero-
any great scientiﬁc accomplishment relies for the most part on the cre-ative abilities of a great mind, Eratosthenes was assisted by the topo-graphical realities of his physical environment. The Nile extends almost due south for 1,000 km. from Alexandria to Syene at the First Cataract: its east-west deviation from this line is no more than 200 km. The route had been carefully measured on the ground by surveyors, most recently in the time of Ptolemaios II,67 and there were reports from farther south and along the Red Sea coast, all published by explorers of Ptolemaios II such as Philon, Pythagoras, Ariston, Bion, and Simias.68 It also was known that at Syene the sun was directly overhead on the summer solstice, and a well in the city demonstrated that there was no shadow at this time of the year.69 Others had attempted to calculate the circumference of the earth, including Eudoxos of Knidos, Aristotle, Dikaiarchos of Mes-sana, and Archimedes:70 Eratosthenes built on these previous attempts and used Euclidean geometry to determine a circumference of 252,000 stadia. His erroneous assumption of a purely spherical earth had little effect.71After publication of the Measurement, Eratosthenes turned to his Geographika, a natural extension of the earlier work. Having calculated the size of the earth, he now described what was on it, and, to some ex-tent, how it was formed. Date of publication would have been between the accession of Ptolemaios III in 246 BC and Eratosthenes’ death ap-proximately 40 years later. His seeming obliviousness to the Roman ex-pansion onto the Greek mainland that began in 218 BC, despite his glyphics from the time of Ptolemaios III by a symbol combining the protractor and plumb bob. See Erich Winter, “Weitere Beobachtungen zur ‘Grammaire du Temple’ in der Griechish-Römischen Zeit,” in Temple und Kult (ed. Wolfgang Helck, Wiesbaden 1987) 72–5.67 A close reading of Martianus Capella’s description of Eratosthenes’ techniques (6.596–8; see infra, p. 266) may indicate that Ptolemaios III had the route resurveyed for Eratosthenes’ beneﬁt, the only suggestion that he received research support (Blomqvist [supra n. 37] 65).68 On the sources for these explorers, see Duane W. Roller, The World of Juba II and Kleopatra Selene (London 2003) 234–5.69 Strabo 17.1.48. Syene, modern Aswan, was essentially the border post at the southern edge of Ptolemaic territory. Its latitude is 24°19, in Hellenistic times about 25–35 km. north of the tropic.70 On these, supra, pp. 6–7, infra, pp. 141–2.71 Fraser, PA vol. 1, pp. 413–15. His original measurement may have been 250,000, adjusted to provide a number divisible by 60: see the edition of Geminos’ Phainomena by James Evans and J. Lennart Berggren, pp. 211–12. Modern calculations make the earth 40,008 km. around the poles and 40,075 at the equator, a minute difference.THE LIFE OF ERATOSTHENES 13
detailed discussion of the Illyrian region where it started (F143–6), may suggest that the work had been completed by that time. He also began developing a chronological theory, a concept that, in a way, was con-nected with his geographical concerns. His ﬁrst work on this topic was the Olympionikai, on Olympic lists,72 which led to a broader chronologi-cal treatise, the Chronographiai,73 the ﬁrst universal chronology of Greek history, from the Sack of Troy to the death of Alexander, calcu-lated at 860 years.One other work connected to Eratosthenes’ geographical scholarship is his poem Hermes, a combination of mythological and didactic mate-rial that described the childhood of the god.74 It contains a Platonic de-scription of the universe, and, most notably, an account of the terrestrial zones, poetically rendering the material in F44–5 of the Geographika.75 There is no speciﬁc date for the poem: thus it is unknown whether it was an anticipation of the Geographika or a poetic version of parts of it. It inﬂuenced both Cicero and Vergil,76 a feature of the interest in Era-tosthenes’ geographical works during Late Republican Rome.Although Eratosthenes wrote in many areas, he is most remembered today for his geography and his chronology, ﬁelds in which, ironically, his views were soon superseded by the evolution of knowledge. His geo-graphical data were seen as obsolete by the time of Strabo, largely be-cause of the rise of Rome and the opening up of the western Mediterra-nean to Greco-Roman culture, and his chronology, although the basis for all later dating of antiquity, soon became buried under the more exten-sive Roman and Christian information. As is the case with many schol-ars noted for their breadth, he had few students. The Souda named four, of which the most famous is Aristophanes of Byzantion, his successor as Librarian, famous for his studies of Greek poets. Mnaseus of Patara in Lykia was a geographer, Menander, probably of Ephesos, an historian, and there was an otherwise-unknown Aristis.7772 FGrHist #241, F4–8; Geus, Eratosthenes 323–32.73 FGrHist #241, F1–3; see also F9–15; Geus, Eratosthenes 313–22.74 Geus, Eratosthenes 110–28.75 Hermes, F16.76 Cicero, de re publica 6.21–2; Vergil, Georgics 1.231–58; see also James S. Romm, The Edges of the Earth in Ancient Thought (Princeton 1992) 128–9.77 Aristophanes of Byzantion was Librarian from the death of Eratosthenes to about 189/6 BC (Fraser, PA vol. 1, pp. 332–3, 459–61. He produced editions of Homer and Hes-iod and was signiﬁcant in canonizing the Greek poets. Mnaseus’ geographical work seems to have been heavily mythological (Athenaios 8.346; Fraser, PA vol. 1, pp. 524–5), and a few fragments survive of the treatise of Menander of Ephesos on the kings of Tyre (FGrHist #783).
In all probability, the ﬁnal work of Eratosthenes is his biography or eulogy of Arsinoë III, the wife of Ptolemaios IV. Ptolemaios III died around 221 BC, and the convulsions thereafter included the murder of his widow Berenike.78 Ptolemaios IV married his sister Arsinoë III, and Eratosthenes became a respected advisor to the young queen, her com-panion at public events.79 Neither of the new monarchs lasted long: Ptolemaios IV died in 204 BC, and the queen, who was to be regent for the six-year-old Ptolemaios V, was promptly murdered by those who wished to have more inﬂuence over the new king.80 She was barely 30 years of age. The composition of the Arsinoë is the last datable event in Eratosthenes’ life, presumably written immediately after her death in 204 BC, although details remain uncertain. He was around 80 and did not survive much longer. When he died he was buried in Alexandria rather than in his hometown, a fact lamented in an epitaph by Diony-sios of Kyzikos.81The Geographika of EratosthenesEratosthenes’ Geographika was a modest work, only three books in length.82 It probably did not survive intact past the second century AC and exists today in 155 fragments, mostly from the geographical trea-tise of Strabo of Amaseia, written in the Augustan period. Strabo quoted Eratosthenes extensively in his own ﬁrst and second books, and through-out his work, providing 105 of the extant fragments. The only other au-thor to make frequent use of the Geographika was Pliny the Elder, with 16 fragments. Scattered sources into Byzantine times provide minor details: the latest is Tzetzes.The earliest extant author to cite the treatise is Julius Caesar.83 Yet it was used extensively in Hellenistic times, especially by Hipparchos and Polybios, and one of the difﬁculties in understanding Eratosthe-nes is that these writers, who were generally ill-disposed toward the Geographika, themselves survive today only as quotations in Strabo’s Geography, which also offers its own criticisms of Eratosthenes’ treatise. 78 Hölbl (supra n. 51) 127–8; on the eulogy, see Geus, Eratosthenes 61–8.79 Athenaios 7.276 (the only extant citation of the Arsinoë).80 Polybios 15.25; Hölbl (supra n. 51) 134.81 Greek Anthology 7.78; the Souda biography records that he died at 80, refusing food because his eyes were weakening.82 Strabo speciﬁcally mentioned the ﬁrst (1.3.23 5 F19), second (1.4.1 5 F25), and third (2.1.1 5 F47) books, but no more.83 Caesar, Gallic War 6.24 (5 F150).THE GEOGRAPHIKA OF ERATOSTHENES 15