§11.1Διὰ τί ἐπὶ τῶν σκυτάλων ῥᾷον τὰ φορτία κομίζεται ἢ ἐπὶ τῶν ἁμαξῶν, ἐχουσῶν τῶν μὲν μεγάλους τροχούς, τῶν δὲ μικρούς;
Why are loads carried more easily on rollers than on wagons, although some of these have large wheels and others small ones?
Ἣ διότι ἐπὶ τῶν σκυτάλων οὐδεμίαν ἔχει πρόσκοψιν, τὸ δὲ ἐπὶ τῶν ἀμαξῶν τὸν ἄξονα, καὶ προσκόπτει αὐτῷ·
Or is it because on rollers there is no resistance, whereas on wagons there is the axle, and there is resistance against it?
ἔκ τε γὰρ τῶν ἄνωθεν πιέζει αὐτὸν καὶ ἐκ τῶν πλαγίων.
For it is pressed both from above and from the sides.
§11.2Τὸ δὲ ἐπὶ τῶν σκυτάλων ἐπὶ δύο τούτων κινεῖται, τῇ τε κάτω χήρᾳ ὑποκειμένῃ καὶ τῷ βάρει τῷ ἐπικειμένῳ·
On the other hand, a load on rollers moves on these two things: the ground lying beneath and the weight lying upon it.
ἐπ’ἀμφοτέρων γὰρ τούτων κυλίεται τῶν τόπων ὁ κύκλος καὶ φερόμενος ὠθεῖται.
For the circle of the roller rotates on both of these places and is pushed forward as it travels.