§1.3#3ἀλλὰ δεῖ νοῆσαι τοῦ λεγομένου ὑφʼ ἡμῶν ἀέρος τὸ μὲν περὶ τὴν γῆν οἷον ὑγρὸν καὶ θερμὸν εἶναι διὰ τὸ ἀτμίζειν τε καὶ ἀναθυμίασιν ἔχειν γῆς, τὸ δὲ ὑπὲρ τοῦτο θερμὸν ἤδη καὶ ξηρόν.
But we must understand that of what is called air by us, the part around the earth is wet and hot, as it were, because of its both vaporizing and having an exhalation from the earth, while the part above this is already hot and dry.
ἔστιν γὰρ ἀτμίδος μὲν φύσις ὑγρὸν καὶ θερμόν, ἀναθυμιάσεως δὲ θερμὸν καὶ ξηρόν· καὶ ἔστιν ἀτμὶς μὲν δυνάμει οἷον ὕδωρ, ἀναθυμίασις δὲ δυνάμει οἷον πῦρ.
For the nature of vapor is wet and hot, and that of exhalation is hot and dry; and vapor is potentially like water, while exhalation is potentially like fire.
τοῦ μὲν οὖν ἐν τῷ ἄνω τόπῳ μὴ συνίστασθαι νέφη ταύτην ὑποληπτέον αἰτίαν εἶναι, ὅτι οὐκ ἔνεστιν ἀὴρ μόνον ἀλλὰ μᾶλλον οἷον πῦρ.
Therefore, we must suppose this to be the cause of clouds not being formed in the upper region: that it contains not only air but rather something like fire.
οὐδὲν δὲ κωλύει καὶ διὰ τὴν κύκλῳ φορὰν κωλύεσθαι συνίστασθαι νέφη ἐν τῷ ἀνωτέρω τόπῳ· ῥεῖν γὰρ ἀναγκαῖον ἅπαντα τὸν κύκλῳ ἀέρα, ὅσος μὴ ἐντὸς τῆς περιφερείας λαμβάνεται τῆς ἀπαρτιζούσης ὥστε τὴν γῆν σφαιροειδῆ εἶναι πᾶσαν·
And nothing prevents clouds from being prevented from forming in the higher region also because of the circular motion; for it is necessary that all the air which moves in a circle flows, except for as much as is contained within the circumference that completes the earth so that it is entirely spherical.
φαίνεται γὰρ καὶ νῦν ἡ τῶν ἀνέμων γένεσις ἐν τοῖς λιμνάζουσι τόποις τῆς γῆς, καὶ οὐχ ὑπερβάλλειν τὰ πνεύματα τῶν ὑψηλῶν ὀρῶν.
For even now, the generation of winds is seen to occur in the stagnant regions of the earth, and the winds do not seem to exceed the high mountains.
ῥεῖ δὲ κύκλῳ διὰ τὸ συνεφέλκεσθαι τῇ τοῦ ὅλου περιφορᾷ.
And it flows in a circle because of being dragged along with the circular motion of the whole.
τὸ μὲν γὰρ πῦρ τῷ ἄνω στοιχείῳ, τῷ δὲ πυρὶ ὁ ἀὴρ συνεχής ἐστιν· ὥστε καὶ διὰ τὴν κίνησιν κωλύεται συγκρίνεσθαι εἰς ὕδωρ, ἀλλʼ ἀεὶ ὅ τι ἄν βαρύνηται μόριον αὐτοῦ ἐκθλιβομένου εἰς τὸν ἄνω τόπον τοῦ θερμοῦ κάτω φέρεται, ἄλλα δʼ ἐν μέρει συναναφέρεται τῷ ἀναθυμιωμένῳ πυρί, καὶ οὕτω συνεχῶς τὸ μὲν ἀέρος διατελεῖ πλῆρες ὂν τὸ δὲ πυρός, καὶ ἀεὶ ἄλλο καὶ ἄλλο γίγνεται ἕκαστον αὐτῶν.
For the fire is continuous with the upper element, and the air with the fire; so that because of the motion too, it is prevented from condensing into water, but always whichever part of it becomes heavy, while the hot is squeezed out into the upper region, is carried downward, and other parts in turn are carried up together with the exhalation-like fire, and thus continually one part remains full of air and another of fire, and each of them is always becoming different and different.
περὶ μὲν οὖν τοῦ μὴ γίγνεσθαι νέφη μηδʼ εἰς ὕδωρ σύγκρισιν, καὶ πῶς δεῖ λαβεῖν περὶ τοῦ μεταξὺ τόπου· τῶν ἄστρων καὶ τῆς γῆς, καὶ τίνος ἐστὶν σώματος πλήρης, τοσαῦτα εἰρήσθω.
About, then, clouds not being formed nor condensation into water occurring, and how we must understand the intermediate region between the stars and the earth, and of what body it is full, let so much be said.
περὶ δὲ τῆς γιγνομένης θερμότητος, ἣν παρέχεται ὁ ἥλιος, μᾶλλον μὲν καθʼ ἑαυτὸ καὶ ἀκριβῶς ἐν τοῖς περὶ αἰσθήσεως προσήκει λέγειν (πάθος γάρ τι τὸ θερμὸν αἰσθήσεώς ἐστιν), διὰ τίνα δʼ αἰτίαν γίγνεται μὴ τοιούτων ὄντων ἐκείνων τὴν φύσιν, λεκτέον καὶ νῦν.
And about the heat that comes to be, which the sun provides, it would be more appropriate to speak by itself and accurately in the treatises On Sensation (for hot is a certain affection of sensation), yet for what cause it comes to be when those bodies are not of such a nature, we must speak even now.
ὁρῶμεν δὴ τὴν κίνησιν ὅτι δύναται διακρίνειν τὸν ἀέρα καὶ ἐκπυροῦν, ὥστε καὶ τὰ φερόμενα τηκόμενα φαίνεσθαι πολλάκις.
Indeed, we see that motion is able to dissolve and set the air on fire, so that even moving bodies are often seen to melt.
τὸ μὲν οὖν γίγνεσθαι τὴν ἀλέαν καὶ τὴν θερμότητα ἱκανή ἐστιν παρασκευάζειν καὶ ἡ τοῦ ἡλίου φορὰ μόνον· ταχεῖάν τε γὰρ δεῖ καὶ μὴ πόρρω εἶναι.
Thus, the occurrence of warmth and heat even the motion of the sun alone is sufficient to produce; for it must be rapid and not far off.
ἡ μὲν οὖν τῶν ἄστρων ταχεῖα μὲν πόρρω δέ, ἡ δὲ τῆς σελήνης κάτω μὲν βραδεῖα δέ· ἡ δὲ τοῦ ἡλίου ἄμφω ταῦτα ἔχει ἱκανῶς.
Now the motion of the stars is rapid but far off, and that of the moon is low but slow; but that of the sun has both of these sufficiently.
τὸ δὲ μᾶλλον γίγνεσθαι ἅμα τῷ ἡλίῳ αὐτῷ τὴν θερμότητα εὔλογον, λαμβάνοντας τὸ ὅμοιον ἐκ τῶν παρʼ ἡμῖν γιγνομένων· καὶ γὰρ ἐνταῦθα τῶν βίᾳ φερομένων ὁ πλησιάζων ἀὴρ μάλιστα γίγνεται θερμός.
And that the heat comes to be more together with the sun itself is reasonable, taking the similarity from what happens among us; for here too, of things carried by force, the neighboring air becomes most hot.
καὶ τοῦτʼ εὐλόγως συμβαίνει· μάλιστα γὰρ ἡ τοῦ στερεοῦ διακρίνει κίνησις αὐτόν.
And this happens reasonably; for the motion of a solid especially dissolves it.
διὰ τε ταύτην οὖν τὴν αἰτίαν ἀφικνεῖται πρὸς τόνδε τὸν τόπον ἡ θερμότης, καὶ διὰ τὸ τὸ περιέχον πῦρ τὸν ἀέρα διαρραίνεσθαι τῇ κινήσει πολλάκις καὶ φέρεσθαι βίᾳ κάτω.
For this cause, then, the heat arrives at this region, and also because the fire surrounding the air is often scattered by the motion and carried downward by force.
σημεῖον δʼ ἱκανὸν ὅτι ὁ ἄνω τόπος οὐκ ἔστι θερμὸς οὐδʼ ἐκπεπυρωμένος καὶ αἱ διαδρομαὶ τῶν ἀστέρων.
And a sufficient sign that the upper region is not hot or set on fire is also the tracks of shooting stars.
ἐκεῖ μὲν γὰρ οὐ γίγνονται, κάτω δέ· καίτοι τὰ μᾶλλον κινούμενα καὶ θᾶττον, ἐκπυροῦται θᾶττον.
For they do not occur there, but below; and yet things that are moved more and faster are set on fire faster.
πρὸς δὲ τούτοις ὁ ἥλιος, ὅσπερ μάλιστα εἶναι δοκεῖ θερμός, φαίνεται λευκὸς ἀλλʼ οὐ πυρόδης ὤν.
In addition to these, the sun, which seems to be most hot, is seen to be white but not fiery.