§2.5#15 ὁ δ᾿ ἥλιος καὶ παύει καὶ συνεξορμᾷ τὰ πνεύματα· ἀσθενεῖς μὲν γὰρ καὶ ὀλίγας οὔσας τὰς ἀναθυμιάσεις μαραίνει τῷ πλείονι θερμῷ τὸ ἐν τῇ ἀναθυμιάσει ἔλαττον ὄν, καὶ διακρίνει.
5 But the sun both ceases and jointly excites the winds; for those exhalations that are weak and few, it extinguishes, the lesser heat in the exhalation being overcome by its own greater heat, and disperses them.
ἔτι δὲ αὐτὴν τὴν γῆν φθάνει ξηραίνων πρὶν γενέσθαι ἔκκρισιν ἀθρόαν, ὥσπερ εἰς πολὺ πῦρ ἐὰν ὀλίγον ἐμπέσῃ ὑπέκκαυμα, φθάνει πολλάκις πρὶν καπνὸν ποιῆσαι κατακαυθέν.
Furthermore, it dries the earth itself beforehand, before a collective secretion occurs, just as if a small amount of fuel falls into a large fire, it is often consumed beforehand before it can produce smoke.
διὰ μὲν οὖν ταύτας τὰς αἰτίας καταπαύει τε τὰ πνεύματα καὶ ἐξ ἀρχῆς γίγνεσθαι κωλύει, τῇ μὲν μαράνσει καταπαύων, τῷ δὲ τάχει τῆς ξηρότητος γίγνεσθαι κωλύων·
For these reasons, then, it both ceases the winds and prevents them from arising at the beginning, ceasing them by extinction, and preventing them from arising by the rapidity of the dryness.
διὸ περὶ Ὠρίωνος ἀνατολὴν μάλιστα γίγνεται νηνεμία, καὶ μέχρι τῶν ἐτησίων καὶ προδρόμων.
Therefore, about the rising of Orion, calm especially occurs, and lasts until the Etesian winds and the Prodromoi.
ὅλως δὲ γίγνονται αἱ νηνεμίαι διὰ δύ᾿ αἰτίας· ἢ γὰρ διὰ ψῦχος ἀποσβεννυμένης τῆς ἀναθυμιάσεως, οἷον ὅταν γένηται πάγος ἰσχυρός, ἢ καταμαραινομένης ὑπὸ τοῦ πνίγους.
In general, calms occur for two reasons: either when the exhalation is extinguished by cold, as when a strong frost occurs, or when it is consumed by the stifling heat.
αἱ δὲ πλεῖσται καὶ ἐν ταῖς ἀνὰ μέσον ὥραις, ἢ τῷ μήπω ἀναθυμιᾶσθαι, ἢ τῷ ἤδη ἐξεληλυθέναι τὴν ἀναθυμίασιν καὶ ἄλλην μήπω ἐπιρρεῖν.
But most of them occur in the intermediate seasons, either because there is no exhalation yet, or because the exhalation has already departed and another has not yet flowed in.
ἄκριτος δὲ καὶ χαλεπὸς ὁ Ὠρίων εἶναι δοκεῖ, καὶ δύνων καὶ ἐπιτέλλων, διὰ τὸ ἐν μεταβολῇ ὥρας συμβαίνειν τὴν δύσιν καὶ τὴν ἀνατολήν, θέρους ἢ χειμῶνος, καὶ διὰ τὸ μέγεθος τοῦ ἄστρου ἡμερῶν γίγνεται πλῆθος· αἱ δὲ μεταβολαὶ πάντων ταραχώδεις διὰ τὴν ἀοριστίαν εἰσίν.
And Orion seems to be uncertain and harsh, both when setting and when rising, because its setting and rising happen at the change of a season, of summer or of winter, and because of the size of the constellation it lasts for many days; and the changes of all things are turbulent because of their indefiniteness.
οἱ δ᾿ ἐτησίαι πνέουσι μετὰ τροπὰς καὶ κυνὸς ἐπιτολήν, καὶ οὔτε τηνικαῦτα ὅτε μάλιστα πλησιάζει ὁ ἥλιος, οὔτε ὅτε πόρρω· καὶ τὰς μὲν ἡμέρας πνέουσι, τὰς δὲ νύκτας παύονται.
And the Etesian winds blow after the solstices and the rising of the Dog Star, and neither at the time when the sun is closest, nor when it is far away; and they blow during the days, but cease during the nights.
αἴτιον δ᾿ ὅτι πλησίον μὲν ὢν φθάνει ξηραίνων πρὶν γενέσθαι τὴν ἀναθυμίασιν· ὅταν δ᾿ ἀπέλθῃ μικρόν, σύμμετρος ἤδη γίγνεται ἡ ἀναθυμίασις καὶ ἡ θερμότης, ὥστε τὰ πεπηγότα ὕδατα τήκεσθαι, καὶ τῆς γῆς ξηραινομένης ὑπό τε τῆς οἰκείας θερμότητος καὶ ὑπὸ τῆς τοῦ ἡλίου οἷον τύφεσθαι καὶ θυμιᾶσθαι.
The cause is that when it is near, it dries beforehand before the exhalation occurs; but when it departs a little, the exhalation and the heat are then moderate, so that the frozen waters melt, and as the earth is dried both by its own heat and by that of the sun, it is as it were smoldered and exhaled.
τῆς δὲ νυκτὸς λωφῶσι διὰ τὸ τὰ πεπηγότα τηκόμενα παύεσθαι διὰ τὴν ψυχρότητα τῶν νυκτῶν.
And during the nights they abate because the melting of the frozen things ceases because of the coldness of the nights.
θυμιᾶται δ᾿ οὔτε τὸ πεπηγὸς οὔτε τὸ μηδὲν ἔχον ξηρόν, ἀλλ᾿ ὅταν ἔχῃ τὸ ξηρὸν ὑγρότητα, τοῦτο θερμαινόμενον θυμιᾶται.
For neither that which is frozen nor that which has nothing dry exhales, but when the dry has moisture, this being heated exhales.
ἀποροῦσι δέ τινες διὰ τί βορέαι μὲν γίγνονται συνεχεῖς, οὓς καλοῦμεν ἐτησίας, μετὰ τὰς θερινὰς τροπάς, νότοι δὲ οὕτως οὐ γίγνονται μετὰ τὰς χειμερινάς.
And some raise a difficulty, why northerly winds, which we call Etesians, arise continuously after the summer solstice, but southerly winds do not arise in this way after the winter solstice.
ἔχει δὲ οὐκ ἀλόγως· γίγνονται μὲν γὰρ οἱ καλούμενοι λευκόνοτοι τὴν ἀντικειμένην ὥραν, οὐχ οὕτως δὲ γίγνονται συνεχεῖς· διὸ λανθάνοντες ποιοῦσιν ἐπιζητεῖν.
But this is not without reason: for those called Leukonotoi arise in the opposite season, but they do not arise so continuously, wherefore being unnoticed they cause people to inquire.
αἴτιον δ᾿ ὅτι ὁ μὲν βορέας ἀπὸ τῶν ὑπὸ τὴν ἄρκτον πνεῖ τόπων, οἳ πλήρεις ὕδατος καὶ χιόνος εἰσὶ πολλῆς, ὧν τηκομένων ὑπὸ τοῦ ἡλίου μετὰ τὰς θερινὰς τροπὰς μᾶλλον ἢ ἐν αὐταῖς πνέουσιν οἱ ἐτησίαι· οὕτω γὰρ καὶ τὰ πνίγη γίγνεται, οὐχ ὅταν μάλιστα πλησιάζῃ πρὸς ἄρκτον, ἀλλ᾿ ὅταν πλείων μὲν ᾖ χρόνος θερμαίνοντι, ἔτι δὲ ἐγγύς.
The cause is that the northerly wind blows from the regions under the north, which are full of water and much snow, which being melted by the sun after the summer solstice rather than at the solstice itself, the Etesian winds blow; for so also the stifling heat occurs, not when it is closest to the north, but when there is more time of its heating, and yet it is near.
ὁμοίως δὲ καὶ μετὰ χειμερινὰς τροπὰς πνέουσιν οἱ ὀρνιθίαι· καὶ γὰρ οὗτοι ἐτησίαι εἰσὶν ἀσθενεῖς· ἐλάττους δὲ καὶ ὀψιαίτεροι τῶν ἐτησίων πνέουσιν· ἑβδομηκοστῇ γὰρ ἄρχονται πνεῖν διὰ τὸ πόρρω ὄντα τὸν ἥλιον ἐνισχύειν ἧττον.
And similarly after the winter solstice blow the Ornithiai; for these too are weak Etesians; but they blow smaller and later than the Etesians; for they begin to blow on the seventieth day, because the sun, being far away, is less strong.
οὐ συνεχεῖς δ᾿ ὁμοίως πνέουσι, διότι τὰ μὲν ἐπιπολῆς καὶ ἀσθενῇ τότε ἀποκρίνεται, τὰ δὲ μᾶλλον πεπηγότα πλείονος δεῖται θερμότητος.
And they do not blow continuously in the same way, because the superficial and weak things are then separated, while those that are more frozen require more heat.
διὸ διαλείποντες οὗτοι πνέουσιν, ἕως ἂν ἐπὶ τροπαῖς πάλιν ταῖς θεριναῖς πνεύσωσιν οἱ ἐτησίαι, ἐπεὶ θέλει γε ὅτι μάλιστα συνεχῶς ἐντεῦθεν ἀεὶ πνεῖν ἄνεμος.
Therefore these blow with intervals, until at the summer solstices again blow the Etesians, since it is indeed the nature of wind to tend to blow from there always as continuously as possible.
ὁ δὲ νότος ἀπὸ τῆς θερινῆς τροπῆς πνεῖ, καὶ οὐκ ἀπὸ τῆς ἑτέρας ἄρκτου.
But the southerly wind blows from the summer solstice, and not from the other pole.