§2.2.1Ἐκτεθείκαμεν δὲ αἰτίας περὶ τῆς γενέσεως τῶν πηγῶν καὶ τῶν ποταμῶν ἐν τῷ ἡμετέρῳ βιβλίῳ τῷ περὶ μετεώρων, ἐν ᾧ εἴπομεν καὶ περὶ σεισμῶν ὅτι πολλάκις δεικνύουσιν οὗτοι πηγὰς καὶ ποταμούς, οἳ πρότερον οὐκ ἐφαίνοντο, οἶον ὅτε σχίζεται ἡ γῆ ἐκ τῆς ἀναθυμιάσεως.
We have set forth the causes of the generation of springs and rivers in our book on meteorology, in which we also spoke about earthquakes, saying that these often show springs and rivers which previously were not appearing, just as when the earth is cleft by the vapor.
Πολλάκις δὲ εὑρίσκομεν ὅτι καὶ πηγαὶ καὶ ποταμοὶ συζεύγνυνται, ὅτε γίνεται σεισμός.
And we often find that both springs and rivers are joined together when an earthquake occurs.
§2.2.2Τοῦτο δὲ τῷ φυτῷ οὐ συμβαίνει, ὅτι ἀὴρ ἐν τῇ ἀραιότητι τῶν μερῶν αὐτοῦ ἐστί, καὶ τοῦδε πάλιν σημεῖον, ὅτι σεισμὸς οὐδὲ ἐν τοῖς τόποις τοῖς ψαμμώδεσι πέφυκε γίνεσθαι, ἀλλ’ ἐν τόποις πυκνοῖς καὶ σκληροῖς, ὁποῖοί εἰσιν οἱ τῶν ὑδάτων καὶ τῶν ὁρέων.
But this does not happen to the plant, because air is in the porosity of its parts. And of this again there is a sign: that an earthquake is not of a nature to occur even in sandy places, but in dense and hard places, such as those of waters and mountains.
§2.2.3Καὶ γὰρ συμβαίνει σεισμὸς ἐν τοῖς τόποις τούτοις, ὅτι τὸ ὕδωρ ἐστὶ στερρὸν καὶ οἱ λίθοι στερροί· τῇ φύσει δὲ τοῦ ἀέρος τοῦ θερμοῦ καὶ ξηροῦ ἔνεστι τὸ ἀναβαίνειν ἐκ τῆς κουφότητος.
For an earthquake happens in these places because the water is solid and the stones are solid; and it belongs to the nature of hot and dry air to ascend due to its lightness.
Ὄτε γοῦν συνέλθωσι τὰ μέρη αὐτοῦ καὶ κατακυριεύσωσι, συνωθοῦσι τὸν τόπον, καὶ ἐντεῦθεν ἐξέρχεται ἀπ’ αὐτοῦ βιαία ἀναθυμίασις.
When, therefore, its parts come together and prevail, they push the place together, and hence a violent vapor comes out from it.
§2.2.4Ἐὰν δὲ ὁ τόπος ἦν ἀραιός, οὐκ ἂν ἐξήρχετο οὕτως, ἀλλ’ ὡς ἐπὶ τῆς ψάμμου συμβαίνει.
And if the place were porous, it would not have come out in this way, but as happens on sand.
Ἐξέρχεται γὰρ καὶ ἐντεῦθεν ἀναθυμίασις, ἀλλὰ κατὰ βραχύ·
For a vapor comes out from there too, but gradually; and therefore no earthquake occurs.
καὶ διὰ τοῦτο οὐ γίνεται σεισμός, Ἁπλῶς οὖν ἐν τοῖς στερεοῖς πᾶσι τοῦτο οὐ συμβαίνει, λέγω τὸ κατὰ βραχὺ τὸν ἀέρα ἐξέρχεσθαι.
Simply, therefore, in all solids this does not happen—I mean, the air coming out gradually.
§2.2.5Συναγόμενα γὰρ τὰ μέρη τούτου δύνανται τὴν γῆν σχίζειν, καὶ τοῦτο ἐστὶν αἰτία τοῦ σεισμοῦ ἐν σώμασι στερεοῖς.
For its parts, being gathered together, are able to cleave the earth, and this is the cause of the earthquake in solid bodies.
Ἐν τοῖς μέρεσι δὲ τῶν φυτῶν καὶ τῶν ζῴων σεισμὸς οὐ γίνεται, ἀλλ’ ἐν ἄλλοις πᾶσι, καὶ πλειστάκις ἔν τε τοῖς ὁστρακώδεσι καὶ ἐν ὑέλῳ καὶ λοιποῖς μετάλλοις.
But in the parts of plants and animals, an earthquake does not occur, but in all other things, and most frequently in testaceous things, glass, and other metals.
§2.2.6Ἐν ᾧ γὰρ σώματί ἐστι πολλὴ ἀραιότης, ἔθος καὶ τὴν ἀναθυμίασιν ἀναβαίνειν· ὑποκουφίζει γὰρ αὐτὴν ὁ ἀήρ.
For in whatever body there is much porosity, it is customary for the vapor to ascend; for the air lightens it from below.
Καὶ συχνάκις τοῦτο βλέπομεν, ὅταν βάλλωμεν χρυσὸν εἰς τὸ ὕδωρ ἢ ἄλλο τι βαρύ, καὶ παραυτίκα βυθίζεται· καὶ πάλιν ὅταν βάλλωμεν ξύλον ἀραιὸν ἤ βραχύ, καὶ ἐπιπλέει καὶ οὐ βυθίζεται.
And we frequently see this: when we throw gold into water or something else heavy, it sinks immediately; and again when we throw wood that is porous or small, it floats and does not sink.
§2.2.7Ὅθεν οὐ διὰ τὰ φύλλα οὐ καταδύεται τὸ καταδυόμενον πολλάκις ξύλον, οὐδὲ διὰ τὸ ὑποκείμενον τὸ βαρύ, ἀλλ’ ὅτι τὸ μέν ἐστι στερρὸν καὶ πυκνόν, τὸ δὲ ἀραιόν· τὸ δὲ ἀραιὸν παντάπαν οὐ βυθίζεται.
Hence, it is not because of the leaves that a wood which often sinks does not sink, nor because of the heavy thing lying beneath, but because the one is solid and dense, and the other is porous; and the porous does not sink at all.
§2.2.8Ἔβενος δὲ καὶ τὰ αὐτῷ παραπλήσια βυθίζονται, ὅτι μικρά ἐστιν ἐν τούτοις ἡ ἀραιότης· καὶ οὐδὲ ἔστιν ἐν αὐτοῖς ἀὴρ ὁ δυνάμενος ταῦτα κουφίσαι.
But ebony and things similar to it sink, because the porosity in these is small; and there is not even air in them that is able to lighten them.
Καταδύονται δέ, ὅτι τὰ μέρη αὐτῶν λίαν εἰσὶ πυκνὰ καὶ στερρά.
And they sink because their parts are exceedingly dense and solid.
Πᾶν δὲ ἔλαιον καὶ πάντα τὰ φύλλα τοῦ ὕδατος ὑπερνήχονται.
But all oil and all leaves swim upon the water.
§2.2.9Καὶ τοῦτο ἤδη ἀποδεικνύομεν.
And this we already prove.
Ἔγνωμεν γὰρ ὅτι ἐν τούτοις ἐστὶν ὑγρότης καὶ θερμότης, καὶ ἔθος τοῦ ὑγροῦ ἐστὶ τοῖς τοῦ ὕδατος μέρεσι συνάπτεσθαι· ἡ δὲ θερμότης ποιεῖ ἀνάγεσθαι τὸ ὑγρόν, καθὼς παρέπεται ἐν τῷ καιρῷ τοῦ ἔαρος.
For we know that in these there is moisture and heat, and it is customary for the moist to be joined to the parts of water; and the heat causes the moist to be raised up, just as follows in the season of spring.
Ἔθος δὲ καὶ τοῦ ὕδατος τὸ κουφίζειν πάντα πρὸς τὴν ἰδίαν ἐπιφάνειαν ἕως τῆς τοῦ ἀέρος ἐπιφανείας, ὥστε ποιεῖν αὐτὸν ἀνέρχεσθαι.
And it is also customary for water to lighten everything toward its own surface up to the surface of the air, so as to make it ascend.