# More Attention to Wheels (Less to Walls)

Pindar, Fr. 194

“Come, let us build walls now,
A speaking, intricate, construction of words”

εἶα τειχίζωμεν ἤδη ποικίλον
κόσμον αὐδάεντα λόγων

Aristotle, Mechanical Problems, 851b

“Why do round and circular things move most easily of all shapes? A wheel has three different types of movement. It can move along the rim of the wheel as the center moves too (the way a wheel of a simple cart turns). It can also move around the center, the way that pulleys do, when the center stays still. Or, it may move parallel to the ground with the center still too, the way a potter’s wheel moves.

These movements are really fast because of the limited friction with the ground—this is the same as how a circle only touches a single point on a line and for that reason there is little resistance.”

Διὰ τί τὰ στρογγύλα καὶ περιφερῆ τῶν σχημάτων εὐκινητότερα; τριχῶς δὲ ἐνδέχεται τὸν κύκλον κυλισθῆναι· ἢ γὰρ κατὰ τὴν ἁψῖδα, συμμεταβάλλοντος τοῦ κέντρου, ὥσπερ ὁ τροχὸς ὁ τῆς ἁμάξης κυλίεται· ἢ περὶ τὸ κέντρον μόνον, ὥσπερ αἱ τροχιλέαι, τοῦ κέντρου μένοντος· ἢ παρὰ τὸ ἐπίπεδον, τοῦ κέντρου μένοντος, ὥσπερ ὁ εραμεικὸς τροχὸς κυλίνδεται. εἰ μὲν δὴ τάχιστα τὰ τοιαῦτα, διά τε τὸ μικρῷ ἅπτεσθαι τοῦ ἐπιπέδου, ὥσπερ ὁ κύκλος κατὰ στιγμήν, καὶ διὰ τὸ μὴ προσκόπτειν·