Γεωγραφικα 2.1.7

2.1.7

ἔτι φησὶν ὁ Ἵππαρχος ἐν τῷ δευτέρῳ ὑπομνήματι αὐτὸν τὸν Ἐρατοσθένη διαβάλλειν τὴν τοῦ Πατροκλέους πίστιν ἐκ τῆς πρὸς Μεγασθένη διαφωνίας περὶ τοῦ μήκους τῆς Ἰνδικῆς τοῦ κατὰ τὸ βόρειον πλευρόν, τοῦ μὲν Μεγασθένους λέγοντος σταδίων μυρίων ἑξακισχιλίων, τοῦ δὲ Πατροκλέους χιλίοις λείπειν φαμένου· ἀπὸ γάρ τινος ἀναγραφῆς σταθμῶν ὁρμηθέντα τοῖς μὲν ἀπιστεῖν διὰ τὴν διαφωνίαν, ἐκείνῃ δὲ προσέχειν. εἰ οὖν διὰ τὴν διαφωνίαν ἐνταῦθα ἄπιστος ὁ Πατροκλῆς, καίτοι παρὰ χιλίους σταδίους τῆς διαφορᾶς οὔσης, πόσῳ χρὴ μᾶλλον ἀπιστεῖν ἐν οἷς παρὰ ὀκτακισχιλίους ἡ διαφορά ἐστι, πρὸς δύο καὶ ταῦτα ἄνδρας συμφωνοῦντας ἀλλήλοις, τῶν μὲν λεγόντων τὸ τῆς Ἰνδικῆς πλάτος δισμυρίων σταδίων, τοῦ δὲ μυρίων καὶ δισχιλίων;

Again, in the second volume of his Commentaries, Hipparchus accuses Eratosthenes of himself throwing discredit on the statement of Patrocles, on account of his differing with Megasthenes, as to the length of India on its northern side; Megasthenes stating the length at 16,000 stadia, and Patrocles at 1000 less. Being biassed by a certain Itinerary, Eratosthenes was led to reject them both on account of this discrepancy, and to follow the Itinerary. If then merely the difference of 1000 stadia is sufficient to cause the authority of Patrocles to be rejected, how much more should this be the case when we find a difference of 8000 stadia between his statement and that of two writers who agree perfectly in theirs, that the breadth of India is 20,000 stadia, while he gives only 12,000!