§2.1.39πλημμελεῖ δὲ καὶ ἐν τῷ ἑξῆς ἐπιχειρήματι, ἐν ᾧ συνάγειν βούλεται, ὅτι τὴν ἀπὸ Θαψάκου ἐπὶ Κασπίους πύλας ὁδόν, ἣν μυρίων σταδίων Ἐρατοσθένης εἴρηκεν, οὐκ ἐπʼ εὐθείας ἀναμεμετρημένην ὡς ἐπʼ εὐθείας παραδίδωσι, τῆς εὐθείας πολὺ ἐλάττονος οὔσης.
He also errs in the next argument, in which he wishes to conclude that the road from Thapsacus to the Caspian Gates, which Eratosthenes has stated to be ten thousand stadia, is not measured in a straight line but is delivered as if in a straight line, although the straight line is much shorter.
ἡ δʼ ἔφοδός ἐστιν αὐτῷ τοιαύτη.
His approach is as follows.
φησὶν εἶναι κατʼ Ἐρατοσθένη τὸν αὐτὸν μεσημβρινὸν τόν τε διὰ τοῦ Κανωβικοῦ στόματος καὶ τὸν διὰ Κυανέων, διέχειν δὲ τοῦτον τοῦ διὰ Θαψάκου ἑξακισχιλίους τριακοσίους σταδίους, τὰς δὲ Κυανέας τοῦ Κασπίου ὄρους ἑξακισχιλίους ἑξακοσίους, ὃ κεῖται κατὰ τὴν ὑπέρθεσιν τὴν ἐπὶ τὸ Κάσπιον πέλαγος ἐκ Κολχίδος, ὥστε παρὰ τριακοσίους σταδίους τὸ ἴσον εἶναι διάστημα ἀπὸ τοῦ διὰ Κυανέων μεσημβρινοῦ ἐπί τε Θάψακον καὶ ἐπὶ τὸ Κάσπιον· τρόπον δή τινα ἐπὶ τοῦ αὐτοῦ μεσημβρινοῦ κεῖσθαι τήν τε Θάψακον καὶ τὸ Κάσπιον·
He says that, according to Eratosthenes, the meridian through the Canopic mouth and the one through the Cyaneae are the same, and that this meridian is six thousand three hundred stadia distant from the one through Thapsacus, and the Cyaneae are six thousand six hundred stadia distant from the Caspian mountain, which lies at the pass leading from Colchis to the Caspian Sea, so that, with a difference of three hundred stadia, the distance from the meridian through the Cyaneae to Thapsacus and to the Caspian mountain is equal; and that in a certain way, both Thapsacus and the Caspian mountain lie on the same meridian.
τούτῳ δʼ ἀκολουθεῖν τὸ ἀφεστάναι ἴσον τὰς Κασπίους πύλας Θαψάκου τε καὶ τοῦ Κασπίου, πολὺ ἐλάττους ἀφεστάναι τῶν μυρίων, ὅσους φησὶν ἀφεστάναι Ἐρατοσθένης τῆς Θαψάκου, ἄρα πολὺ ἐλάττους ἢ μυρίους ἀφεστάναι τοὺς ἐπʼ εὐθείας.
And from this, he says, it follows that the Caspian Gates are equally distant from both Thapsacus and the Caspian mountain, being distant by much less than the ten thousand stadia which Eratosthenes says they are distant from Thapsacus, and therefore the straight-line distance is much less than ten thousand.
κυκλοπορίαν ἄρα εἶναι τοὺς μυρίους, λογίζεται ἐκεῖνος ἐπʼ εὐθείας ἀπὸ Κασπίων πυλῶν εἰς Θάψακον.
Thus, he calculates that the ten thousand is a roundabout route, while Eratosthenes calculates in a straight line from the Caspian Gates to Thapsacus.
ἐροῦμεν δὲ πρὸς αὐτόν, ὅτι τοῦ Ἐρατοσθένους ἐν πλάτει λαμβάνοντος εὐθείας, ὅπερ οἰκεῖόν ἐστι γεωγραφίας, ἐν πλάτει δὲ καὶ τὰς μεσημβρινὰς καὶ τὰς ἐπὶ ἰσημερινὴν ἀνατολήν, ἐκεῖνος γεωμετρικῶς αὐτὸν εὐθύνει καὶ ὡς ἂν διʼ ὀργάνων λάβοι τις τούτων ἕκαστον, οὐδὲ αὐτὸς διʼ ὀργάνων ἀλλὰ μᾶλλον στοχασμῷ λαμβάνων καὶ τὸ πρὸς ὀρθὰς καὶ τὸ παραλλήλους.
But we shall say to him that, while Eratosthenes takes straight lines with a certain latitude, which is appropriate to geography, and likewise takes both meridians and lines towards the equinoctial sunrise with latitude, Hipparchus corrects him geometrically, as if one would take each of these with instruments, though he himself does not take either right angles or parallels with instruments but rather by conjecture.
ἓν μὲν δὴ τοῦθʼ ἁμάρτημα· ἕτερον δὲ τὸ μηδὲ τὰ κείμενα παρʼ ἐκείνῳ διαστήματα τίθεσθαι ὑπʼ αὐτοῦ, μηδὲ πρὸς ἐκεῖνα τὸν ἔλεγχον προσάγεσθαι, ἀλλὰ πρὸς τὰ ὑπʼ αὐτοῦ πλαττόμενα.
This is indeed one error; another is that the distances laid down by Eratosthenes are not even assumed by him, nor is the refutation brought against them, but against those fabricated by himself.
διόπερ πρῶτον μὲν ἐκείνου τὸ ἀπὸ τοῦ στόματος ἐπὶ Φᾶσιν εἰπόντος σταδίων ὀκτακισχιλίων, καὶ προσθέντος τοὺς εἰς Διοσκουριάδα ἐνθένδε ἑξακοσίους, τὴν δʼ ἀπὸ Διοσκουριάδος εἰς τὸ Κάσπιον ὑπέρθεσιν ἡμερῶν πέντε, ἥτις κατʼ αὐτὸν Ἵππαρχον εἰκάζεται λέγεσθαι ὅσον χιλίων σταδίων, ὥστε τὴν σύμπασαν κατʼ Ἐρατοσθένη κεφαλαιοῦσθαι ἐννακισχιλίων ἑξακοσίων· αὐτὸς συντέτμηκε καὶ φησὶν ἐκ μὲν Κυανέων εἰς Φᾶσιν πεντακισχιλίους ἑξακοσίους, εἰς δὲ Κάσπιον ἐνθένδε ἄλλους χιλίους· ὥστʼ οὐ κατʼ Ἐρατοσθένη συμβαίνοι ἂν ἐπὶ τοῦ αὐτοῦ πως μεσημβρινοῦ τό τε Κάσπιον εἶναι καὶ τὴν Θάψακον, ἀλλὰ κατʼ αὐτόν.
For whereas Eratosthenes spoke of the distance from the mouth to Phasis as eight thousand stadia, and added the six hundred from there to Dioscurias, and the pass from Dioscurias to the Caspian mountain as a journey of five days, which according to Hipparchus himself is conjectured to be spoken of as about a thousand stadia, so that the sum total according to Eratosthenes amounts to nine thousand six hundred; Hipparchus himself has shortened it and says that from the Cyaneae to Phasis is five thousand six hundred, and from there to the Caspian mountain another thousand; so that it would not be according to Eratosthenes that the Caspian mountain and Thapsacus are on somehow the same meridian, but according to himself.
φέρε δʼ οὖν κατʼ Ἐρατοσθένη· πῶς οὖν τούτῳ ἕπεται τὸ τὴν ἀπὸ τοῦ Κασπίου ἐπὶ Κασπίους πύλας ἴσην εἶναι τῇ ἀπὸ Θαψάκου ἐπὶ τὸ αὐτὸ σημεῖον;
But let it be according to Eratosthenes; how then does it follow from this that the distance from the Caspian mountain to the Caspian Gates is equal to that from Thapsacus to the same point?