§2.3.1πολύβιος δὲ ποιεῖ ζώνας ἕξ, δύο μὲν τὰς τοῖς ἀρκτικοῖς ὑποπιπτούσας, δύο δὲ τὰς μεταξὺ τούτων τε καὶ τῶν τροπικῶν, καὶ τοῦ ἰσημερινοῦ.
Polybius makes six zones: two falling under the polar circles, two between these and the tropics, and [two] of the equator.
ἡ μὲν οὖν εἰς πέντε διαίρεσις δοκεῖ μοι καὶ φυσικῶς ἅμα καὶ γεωγραφικῶς εἰρῆσθαι· φυσικῶς μέν, ὅτι καὶ πρὸς τὰ οὐράνια καὶ πρὸς τὴν τοῦ περιέχοντος κρᾶσιν· πρὸς μὲν τὰ οὐράνια, ὅτι τοῖς περισκίοις καὶ τοῖς ἀμφισκίοις οὕτως ἂν ἄριστα διοριζομένοις συνδιορίζεται καὶ τὰ περὶ τὴν θέαν τῶν ἄστρων, ὁλοσχερεῖ τινι μερισμῷ λαμβάνοντα τὴν ἐξάλλαξιν· πρὸς δὲ τὴν τοῦ περιέχοντος κρᾶσιν, ὅτι τῆς τούτου κράσεως πρὸς τὸν ἥλιον κρινομένης διαφοραὶ τρεῖς εἰσιν αἱ γενικώταται καὶ συντείνουσαι πρός τε τὰς τῶν ζῴων καὶ φυτῶν συστάσεις καὶ τῶν ἄλλων * ἡμισυσταλεῖς τῶν ὑπὸ τῷ ἀέρι καὶ ἐν αὐτῷ ἐκείνῳ, ὑπερβολὴ θάλπους καὶ ἔλλειψις καὶ μεσότης.
Now, the division into five zones seems to me to be stated both physically and geographically at the same time: physically, because it adapts both to celestial phenomena and to the temperature of the atmosphere; to celestial phenomena, because for the periscian and amphiscian zones, when they are thus best defined, the observations of the stars are also co-defined, receiving their variations in a broad division; and to the temperature of the atmosphere, because when its temperature is judged in relation to the sun, there are three most general differences which contribute to the constitution of animals and plants, and of other half-shrivelled things under the air and in that very air, namely, excess, deficiency, and mediocrity of heat.
αὕτη δὲ τῷ εἰς τὰς ζώνας μερισμῷ λαμβάνει τὴν οἰκείαν διάκρισιν· αἵ τε γὰρ κατεψυγμέναι δύο τὴν ἔλλειψιν τοῦ θάλπους ὑπαγορεύουσιν εἰς μίαν τοῦ περιέχοντος φύσιν συναγόμεναι, αἵ τε εὔκρατοι παραπλησίως εἰς μίαν τὴν μεσότητα ἄγονται, εἰς δὲ τὴν λοιπὴν ἡ λοιπὴ μία καὶ διακεκαυμένη.
And this (threefold difference) receives its proper distinction by the division into the zones; for the two frozen zones indicate the deficiency of heat, being brought together into one nature of the atmosphere, and the two temperate zones are likewise led into one mediocrity, while to the remaining difference belongs the remaining one, the scorched zone.
ὅτι δὲ καὶ γεωγραφικός ἐστιν ὁ μερισμός, δῆλον· ζητεῖ γὰρ ἡ γεωγραφία τῆς ἑτέρας τῶν εὐκράτων ἀφορίσαι τὸ οἰκούμενον ὑφʼ ἡμῶν τμῆμα· πρὸς δύσει μὲν οὖν καὶ ἀνατολῇ θάλαττά ἐστιν ἡ περατοῦσα, πρὸς δὲ τὰ νότια καὶ τὰ βόρεια ὁ ἀήρ, ὁ μὲν μέσος εὔκρατος ὢν καὶ φυτοῖς καὶ ζῴοις, ὁ δʼ ἐφʼ ἑκάτερα δύσκρατος ὑπερβολῇ καὶ ἐλλείψει τοῦ θάλπους.
And that the division is also geographical is clear; for geography seeks to define the inhabited part by us in one of the two temperate zones; now on the west and east it is the sea that bounds it, and on the south and north the air, the middle part being temperate and suitable for plants and animals, while the parts on either side are intemperate through excess and deficiency of heat.
εἰς δὲ τὰς τρεῖς διαφορὰς ταύτας ἐδέησε τῆς εἰς πέντε ζώνας διαιρέσεως· τῷ γὰρ ἰσημερινῷ τμηθεῖσα δίχα ἡ σφαῖρα τῆς γῆς εἴς τε τὸ βόρειον ἡμισφαίριον, ἐν ᾧ ἡμεῖς ἐσμεν, καὶ τὸ νότιον ὑπέγραψε τὰς τρεῖς διαφοράς· τὰ μὲν γὰρ πρὸς τῷ ἰσημερινῷ καὶ τῇ διακεκαυμένῃ ζώνῃ διὰ καῦμα ἀοίκητά ἐστι, τὰ δὲ πρὸς τῷ πόλῳ διὰ ψῦχος, τὰ δὲ μέσα τὰ εὔκρατα καὶ τὰ οἰκήσιμα.
And for these three differences, the division into five zones was necessary; for the sphere of the earth, being cut in two by the equator into the northern hemisphere, in which we are, and the southern, outlined the three differences; for the parts near the equator and the scorched zone are uninhabitable because of heat, while those near the pole are so because of cold, and the middle parts are temperate and habitable.
ὁ δὲ τὰς ὑπὸ τοῖς τροπικοῖς προστιθεὶς οὐκ ἀνὰ λόγον ταῖς πέντε ταύτας προστίθησιν οὐδʼ ὁμοίᾳ κεχρημένας διαφορᾷ, ἀλλʼ ὡς ἂν εἰ καὶ ταῖς ἐθνικαῖς διαφοραῖς ἀπέφαινε ζώνας, ἄλλην μὲν τὴν Αἰθιοπικήν, ἄλλην δὲ τὴν Σκυθικὴν καὶ Κελτικήν, τρίτην δὲ τὴν ἀνὰ μέσον.
But he who adds the zones under the tropics does not add these to the five zones on any rational principle, nor as making use of a similar difference, but just as if he were representing zones by ethnic differences, making one the Ethiopian zone, another the Scythian and Celtic, and a third the intermediate zone.