§19.1Διὰ τί, ἐὰν μέν τις ἐπιθῇ ἐπὶ τὸ ξύλον πέλεκυν μέγαν καὶ φορτίον μέγαἐπ’ αὐτῷ, οὐ διαιρεῖ τὸ ξύλον, ὅ τι καὶ λόγου ἄξιον· ἐὰν δὲ ἄρας τὸν πέλεκύν τις πατάξῃ αὐτῷ, διασχίζει, ἔλαττον βάρος ἔχοντος τοῦ τύπτοντος πολὺ μᾶλλον ἢ τοῦ ἐπικειμένου καὶ πιεζοῦντος;
Why is it that, if one places a large axe on the wood and a heavy load on top of it, it does not split the wood to any extent worth mentioning; but if, having raised the axe, one strikes with it, it splits it, although the striking body has a much smaller weight than that which lies upon it and presses down?
Ἢ διότι πάντα τῇ κινήσει ἐργάζεται, καὶ τὸ βαρύ τὴν τοῦ βάρους κίνησιν λαμβάνει μᾶλλον κινούμενον ἢ ἠρεμοῦν;
Or is it because all things produce their effect by motion, and a heavy object acquires the motion of its weight more when it is moving than when it is at rest?
§19.2Ἐπικείμενον οὖν οὐ κινεῖται τὴν τοῦ βάρους κίνησιν, φερόμενον δὲ ταύτην τε καὶ τὴν τοῦ τύπτοντος, Ἔτι δὲ καὶ γίνεται σφὴν ὁ πέλεκυς·
Therefore, when lying upon it, it does not move with the motion of its weight; but when in motion, it moves with both this and the motion of the striker.
ὁ δὲ σφὴν μικρὸς ὤν μεγάλα διίστησι διὰ τὸ εἶναι ἐκ δύο μοχλῶν ἐναντίως συγκειμένων.
Moreover, the axe also becomes a wedge; and the wedge, though small, separates great things because it consists of two levers put together in opposite directions.