§2.4#14 περὶ δὲ πνευμάτων λέγωμεν, λαβόντες ἀρχὴν τὴν εἰρημένην ἡμῖν ἤδη πρότερον.
4 Let us speak of winds, taking as our starting point the principle already stated by us before.
ἔστι γὰρ δύ᾿ εἴδη τῆς ἀναθυμιάσεως, ὥς φαμεν, ἡ μὲν ὑγρὰ ἡ δὲ ξηρά· καλεῖται δ᾿ ἡ μὲν ἀτμίς, ἡ δὲ τὸ μὲν ὅλον ἀνώνυμος, τῷ δ᾿ ἐπὶ μέρους ἀνάγκη χρωμένους καθόλου προσαγορεύειν αὐτὴν οἷον καπνόν· ἔστι δ᾿ οὔτε τὸ ὑγρὸν ἄνευ τοῦ ξηροῦ οὔτε τὸ ξηρὸν ἄνευ τοῦ ὑγροῦ, ἀλλὰ πάντα ταῦτα λέγεται κατὰ τὴν ὑπεροχήν.
For there are two kinds of exhalation, as we say, the one moist and the other dry; and the one is called vapor, while the other as a whole is nameless, but because we must use a specific term we must call it universally by some such name as smoke; yet neither the moist exists without the dry nor the dry without the moist, but all these are named according to that which predominates.
φερομένου δὴ τοῦ ἡλίου κύκλῳ, καὶ ὅταν μὲν πλησιάζῃ, τῇ θερμότητι ἀνάγοντος τὸ ὑγρόν, πορρωτέρω δὲ γιγνομένου διὰ τὴν ψύξιν συνισταμένης πάλιν τῆς ἀναχθείσης ἀτμίδος εἰς ὕδωρ (διὸ χειμῶνός τε μᾶλλον γίγνεται τὰ ὕδατα, καὶ νύκτωρ ἢ μεθ᾿ ἡμέραν·
Now, as the sun moves in its circle, when indeed it approaches, it draws up the moisture by its heat, but when it goes further away, because of the cold, the vapor that was drawn up condenses again into water (which is why rain occurs more in winter, and by night rather than by day; though it does not seem so, because what happens at night escapes notice more than what happens by day).
ἀλλ᾿ οὐ δοκεῖ, διὰ τὸ λανθάνειν τὰ νυκτερινὰ τῶν μεθ᾿ ἡμέραν μᾶλλον), τὸ δὴ κατιὸν ὕδωρ διαδίδοται πᾶν εἰς τὴν γῆν, ὑπάρχει δ᾿ ἐν τῇ γῇ πολὺ πῦρ καὶ πολλὴ θερμότης, καὶ ὁ ἥλιος οὐ μόνον τὸ ἐπιπολάζον τῆς γῆς ὑγρὸν ἕλκει, ἀλλὰ καὶ τὴν γῆν αὐτὴν ξηραίνει θερμαίνων·
This descending water is all distributed into the earth, and there exists in the earth much fire and much heat, and the sun not only draws up the moisture on the surface of the earth, but also dries the earth itself by heating it.
τῆς δ᾿ ἀναθυμιάσεως, ὥσπερ εἴρηται, διπλῆς οὔσης, τῆς μὲν ἀτμιδώδους τῆς δὲ καπνώδους, ἀμφοτέρας ἀναγκαῖον γίγνεσθαι.
Since the exhalation, as has been said, is twofold, the one vaporous and the other smoky, it is necessary that both should arise.
τούτων δ᾿ ἡ μὲν ὑγροῦ πλέον ἔχουσα πλῆθος ἀναθυμίασις ἀρχὴ τοῦ ὑομένου ὕδατός ἐστιν, ὥσπερ εἴρηται πρότερον, ἡ δὲ ξηρὰ τῶν πνευμάτων ἀρχὴ καὶ φύσις πάντων.
Of these, the exhalation which contains a greater amount of moisture is the source of rain water, as was said before, while the dry one is the source and nature of all winds.
ταῦτα δὲ ὅτι τοῦτον τὸν τρόπον ἀναγκαῖον συμβαίνειν, καὶ ἐξ αὐτῶν τῶν ἔργων δῆλον· καὶ γὰρ τὴν ἀναθυμίασιν διαφέρειν ἀναγκαῖον, καὶ τὸν ἥλιον καὶ τὴν ἐν τῇ γῇ θερμότητα ταῦτα ποιεῖν οὐ μόνον δυνατὸν ἀλλ᾿ ἀναγκαῖόν ἐστιν.
That these things must happen in this way is clear also from the facts themselves; for the exhalation must differ, and that the sun and the heat in the earth produce these effects is not only possible but necessary.
ἐπειδὴ δ᾿ ἕτερον ἑκατέρας τὸ εἶδος, φανερὸν ὅτι διαφέρει, καὶ οὐχ ἡ αὐτή ἐστιν ἥ τε ἀνέμου φύσις καὶ ἡ τοῦ ὑομένου ὕδατος, καθάπερ τινὲς λέγουσιν· τὸν γὰρ αὐτὸν ἀέρα κινούμενον μὲν ἄνεμον εἶναι, συνιστάμενον δὲ πάλιν ὕδωρ.
Since the form of each is different, it is manifest that they differ, and the nature of wind is not the same as that of rain water, as some say; for they say that the same air when in motion is wind, and when it condenses again, it is water.
ὁ μὲν οὖν ἀήρ, καθάπερ ἐν τοῖς πρὸ τούτων λόγοις εἰρήκαμεν, γίγνεται ἐκ τούτων· ἡ μὲν γὰρ ἀτμὶς ὑγρὸν καὶ ψυχρόν (εὐόριστον μὲν γὰρ ὡς ὑγρόν, διὰ δὲ τὸ ὕδατος εἶναι ψυχρὸν τῇ οἰκείᾳ φύσει, ὥσπερ ὕδωρ μὴ θερμανθέν), ὁ δὲ καπνὸς θερμὸν καὶ ξηρόν· ὥστε καθάπερ ἐκ συμβόλων, συνίσταιτο ἂν ὁ ἀὴρ ὑγρὸς καὶ θερμός.
Now air, as we have said in the discussions before this, arises from these; for vapor is moist and cold (for it is easily bounded as a moist thing, and because it is of water, it is cold in its own nature, like water that has not been heated), while smoke is hot and dry; so that, as if from symbols, air would be constituted as moist and hot.
καὶ γὰρ ἄτοπον εἰ ὁ περὶ ἑκάστους περικεχυμένος ἀὴρ οὗτος γίγνεται κινούμενος πνεῦμα, καὶ ὅθεν ἂν τύχῃ κινηθείς, ἄνεμος ἔσται, ἀλλ᾿ οὐ καθάπερ τοὺς ποταμοὺς ὑπολαμβάνομεν οὐχ ὁπωσοῦν τοῦ ὕδατος εἶναι ῥέοντος, οὐδ᾿ ἂν ἔχῃ πλῆθος, ἀλλὰ δεῖ πηγαῖον εἶναι τὸ ῥέον· οὕτω γὰρ καὶ περὶ τῶν ἀνέμων ἔχει· κινηθείη γὰρ ἂν πολὺ πλῆθος ἀέρος ὑπό τινος μεγάλης πτώσεως, οὐκ ἔχον ἀρχὴν οὐδὲ πηγήν.
For indeed it is absurd if this air poured around each of us becomes wind when in motion, and wherever it happens to be moved, it will be wind, rather than as we conceive of rivers, that they are not just any water flowing anyhow, even if it is in great quantity, but the flowing water must come from a spring; for so it is also with the winds; for a great quantity of air might be moved by some great fall, without having a source or a spring.
μαρτυρεῖ δὲ τὰ γιγνόμενα τοῖς εἰρημένοις· διὰ γὰρ τὸ συνεχῶς μὲν μᾶλλον δὲ καὶ ἧττον καὶ πλείω καὶ ἐλάττω γίγνεσθαι τὴν 360b ἀναθυμίασιν, ἀεὶ νέφη τε καὶ πνεύματα γίγνεται κατὰ τὴν ὥραν ἑκάστην ὡς πέφυκεν·
And what happens bears witness to what has been said; for because the exhalation arises continuously, but now more and now less, and in greater and lesser amounts, 360b clouds and winds are always produced according to each season as is natural.
διὰ δὲ τὸ ἐνίοτε μὲν τὴν ἀτμιδώδη γίγνεσθαι πολλαπλασίαν ὁτὲ δὲ τὴν ξηρὰν καὶ καπνώδη, ὁτὲ μὲν ἔπομβρα τὰ ἔτη γίγνεται καὶ ὑγρά, ὁτὲ δὲ ἀνεμώδη καὶ αὐχμοί.
And because sometimes the vaporous exhalation becomes many times greater, and at other times the dry and smoky one, sometimes the years become rainy and wet, and sometimes windy and dry.
ὁτὲ μὲν οὖν συμβαίνει καὶ τοὺς αὐχμοὺς καὶ τὰς ἐπομβρίας πολλοὺς ἄμα καὶ κατὰ συνεχῆ γίγνεσθαι χώραν, ὁτὲ δὲ κατὰ μέρη·
Sometimes, then, it happens that both the droughts and the rainy seasons occur over a large area and a continuous territory at the same time, and sometimes they occur part by part.
πολλάκις γὰρ ἡ μὲν κύκλῳ χώρα λαμβάνει τοὺς ὡραίους ὄμβρους ἢ καὶ πλείους, ἐν δέ τινι μέρει ταύτης αὐχμός ἐστιν· ὁτὲ δὲ τοὐναντίον τῆς κύκλῳ πάσης ἢ μετρίοις χρωμένης ὕδασιν ἢ καὶ μᾶλλον αὐχμώσης, ἕν τι μόριον ὕδατος ἄφθονον λαμβάνει πλῆθος.
For often the surrounding country receives its seasonal rains or even more, while in some part of it there is a drought; and at other times the opposite, when all the surrounding country either enjoys moderate rains or is rather dry, a single portion receives an abundant quantity of water.
αἴτιον δ᾿ ὅτι ὡς μὲν τὰ πολλὰ τὸ αὐτὸ πάθος ἐπὶ πλείω διήκειν εἰκὸς χώραν, διὰ τὸ παραπλησίως κεῖσθαι πρὸς τὸν ἥλιον τὰ σύνεγγυς, ἐὰν μή τι διάφορον ἔχωσιν ἴδιον· οὐ μὴν ἀλλ᾿ ἐνίοτε κατὰ τοδὶ μὲν τὸ μέρος ἡ ξηρὰ ἀναθυμίασις ἐγένετο πλείων, κατὰ δὲ τὸ ἄλλο ἡ ἀ ὁτὲ δὲ τοὐναντίον.
The cause is that, for the most part, the same affection is likely to extend over a wider country, because neighboring places lie in a similar position relative to the sun, unless they have some distinctive local characteristic; nevertheless, sometimes in this part the dry exhalation becomes greater, while in the other part the vaporous exhalation does, and at other times the opposite.
καὶ αὐτοῦ δὲ τούτου αἴτιον τὸ ἑκατέραν μεταπίπτειν εἰς τὴν τῆς ἐχομένης χώρας ἀναθυμίασιν, οἷον ἡ μὲν ξηρὰ κατὰ τὴν οἰκείαν ῥεῖ χώραν, ἡ δ᾿ ὑγρὰ πρὸς τὴν γειτνιῶσαν, ἢ καὶ εἰς τῶν πόρρω τινὰ τόπων ἀπεώσθη ὑπὸ πνευμάτων· ὁτὲ δὲ αὕτη μὲν ἔμεινεν, ἡ δ᾿ ἐναντία ταὐτὸν ἐποίησεν.
And the cause of this very thing is that each of the two exhalations shifts into that of the adjacent country, as for instance the dry exhalation flows in its own region, while the moist one flows to the neighboring region, or is even pushed away to some of the distant places by the winds; and at other times this one remains, while the opposite one does the same.