Γεωγραφικά 2.1.33

2.1.33

Ἐρατοσθένης δὲ τὸ μὲν τῆς οἰκουμένης λαμβάνει μῆκος ἐπὶ τῆς διὰ στηλῶν καὶ Κασπίων πυλῶν καὶ Καυκάσου γραμμῆς, ὡς ἂν εὐθείας, τὸ δὲ τῆς τρίτης μερίδος ἐπὶ τῆς διὰ Κασπίων πυλῶν καὶ Θαψάκου, τὸ δὲ τῆς τετάρτης ἐπὶ τῆς διὰ Θαψάκου καὶ Ἡρώων πόλεως μέχρι τῆς μεταξὺ τῶν στομάτων τοῦ Νείλου, ἀνάγκη καταστρέφειν εἰς τοὺς περὶ Κάνωβον καὶ Ἀλεξάνδρειαν τόπους· ἐνταῦθα γάρ ἐστι τὸ ἔσχατον στόμα τὸ καλούμενον Κανωβικόν τε καὶ Ἡρακλεωτικόν. εἴτʼ οὖν ἐπʼ εὐθείας ἀλλήλοις τὰ μήκη τίθησιν, εἴθʼ ὡς ἂν γωνίαν ποιοῦντα κατὰ Θάψακον, ἀλλʼ ὅτι γε οὐ παράλληλον οὐδέτερον τῷ τῆς οἰκουμένης μήκει, φανερόν ἐστιν ἐξ αὐτῶν ὧν εἴρηκεν αὐτός. τὸ μὲν γὰρ τῆς οἰκουμένης μῆκος διὰ τοῦ Ταύρου γράφει καὶ τῆς ἐπʼ εὐθείας μέχρι στηλῶν θαλάττης κατὰ γραμμὴν τὴν διὰ τοῦ Καυκάσου καὶ Ῥόδου καὶ Ἀθηνῶν, ἀπὸ δὲ Ῥόδου εἰς Ἀλεξάνδρειαν κατὰ τὸν διʼ αὐτῶν μεσημβρινὸν οὐ πολὺ ἐλάττους τῶν τετρακισχιλίων φησὶν εἶναι σταδίων, ὥστε τοσοῦτον καὶ οἱ παράλληλοι διέχοιεν ἂν ἀλλήλων ὅ τε διὰ Ῥόδου καὶ ὁ διʼ Ἀλεξανδρείας. ὁ δʼ αὐτός πώς ἐστι τούτῳ ὁ διὰ τῆς Ἡρώων πόλεως, ἢ νοτιώτερός γε τούτου, ὥσθʼ ἡ συμπίπτουσα γραμμὴ τούτῳ τε τῷ παραλλήλῳ καὶ τῷ διὰ Ῥόδου καὶ Κασπίων πυλῶν, εἴτʼ εὐθεῖα εἴτε κεκλασμένη, οὐκ ἂν εἴη παράλληλος οὐδετέρᾳ. οὐκ εὖ γοῦν λαμβάνεται τὰ μήκη, οὐκ εὖ δὲ οὐδὲ αἱ βόρειοι λαμβάνονται μερίδες.

Eratosthenes, however, measures the length of the habitable earth by a line which he considers straight, drawn from the Pillars of Hercules, in the direction of the Caspian Gates and the Caucasus. The length of the third section, by a line drawn from the Caspian Gates to Thapsacus, and of the fourth, by one running from Thapsacus through Heroopolis to the country surrounded by the Nile: this must necessarily be deflected to Canopus and Alexandria, for there is the last mouth of the Nile, which goes by the name of the Canopic or Heracleotic mouth. Whether therefore these two lengths be considered to form one straight line, or to make an angle with Thapsacus, certain it is that neither of them is parallel to the length of the habitable earth; this is evident from what Eratosthenes has himself said concerning them. According to him the length of the habitable earth is described by a right line running through the Taurus to the Pillars of Hercules, in the direction of the Caucasus, Rhodes, and Athens. From Rhodes to Alexandria, following the meridian of the two cities, he says there cannot be much less than 4000 stadia, consequently there must be the same difference between the latitudes of Rhodes and Alexandria. Now the latitude of Heroopolis is about the same as Alexandria, or rather more south. So that a line, whether straight or broken, which intersects the parallel of Heroopolis, Rhodes, or the Gates of the Caspian, cannot be parallel to either of these. These lengths therefore are not properly indicated, nor are the northern sections any better.