Eratosthenes of Cyrene
FGrH 241 (circumference) — Eratosthenes, Geographika — earth's circumference (Cleomedes, Caelestia 1.7); cf. FGrH 241 (chronogr./lit. only) Converged in-span
Ὑπὸ τῷ αὐτῷ κεῖσθαι μεσημβρινῷ φησι Συήνην καὶ Ἀλεξάνδρειαν. ἐπεὶ οὖν μέγιστοι τῶν ἐν τῷ κόσμῳ οἱ μεσημβρινοί, δεῖ καὶ τοὺς ὑποκειμένους τούτοις τῆς γῆς κύκλους μεγίστους εἶναι ἀναγκαίως … ἡ δέ γε ἐν τῇ σκάφῃ πεντηκοστὸν μέρος εὑρίσκεται τοῦ οἰκείου κύκλου. ἔστι οὖν ἀναγκαίως καὶ τὸ ἀπὸ Συήνης εἰς Ἀλεξάνδρειαν διάστημα πεντηκοστὸν εἶναι μέρος τοῦ μεγίστου τῆς γῆς κύκλου· καὶ ἔστι τοῦτο σταδίων πεντακισχιλίων. ὁ ἄρα σύμπας κύκλος γίνεται μυριάδων εἴκοσι πέντε. καὶ ἡ μὲν Ἐρατοσθένους ἔφοδος τοιαύτη.
He says that Syene and Alexandria lie under the same meridian. Since meridians are the greatest circles in the cosmos, the terrestrial circles beneath them must necessarily be greatest also ... The arc in the sundial-bowl is found to be a fiftieth part of its own circle. Therefore the distance from Syene to Alexandria must also be a fiftieth part of the earth's greatest circle; and this is 5,000 stadia. So the whole circle comes to 250,000 stadia. Such is Eratosthenes' method.
Apparatus — BNJ base vs open-corpus witness
Base text after Brill’s New Jacoby / Jacoby (FGrH). The apparatus records differences against the open-corpus witness (Cleomedes, Caelestia) within the overlapping span; encoding and orthography are folded. Collation codepoint-verified and adversarially audited (2026-06-26).
| Lemma / locus | BNJ base | Witness | Type | Note |
|---|
| No substantive differences in the witnessed span — the BNJ base is verbatim against the open-corpus witness (encoding/orthography folded). |
Witness: Cleomedes, Caelestia. Verdict: CONVERGED-IN-SPAN. In-span: the candidate extends slightly beyond the open-corpus witness; the apparatus covers only the witnessed portion.
Open-corpus witness family: urn:cts:greekLit. This is a BNJ/Jacoby-based edition with an open-corpus apparatus, not a verbatim copy of the witness edition. Source data: explorers/_build/editions/ecoed-erat-fgrh241-circumference.json.