Πολύκλειτος ὁ πλάστης εἶπε χαλεπώτατον εἶναι τοὔργον, ὅταν ἐν ὄνυχι ὁ πηλὸς γένηται.
If we interpret this passage as referring to a potter, and ὅταν ἐν ὄνυχι γένηται as meaning when the stage has been reached that the clay is hard enough to be scratched with the nail, this may possibly be an allusion to turning; which may well be called the most difficult process of pottery making. But this interpretation is very uncertain. The passage is usually taken as referring to the sculptor’s last touches on a clay model for a bronze statue.
(2) BUILDING
Geoponica, VI, 3 (4).
4. Potters do not use the wheel for all pithoi, but only for the small ones. The larger ones they build up day by day, placing them on the ground in a warm room, and thus make them large.
4. Οὐ πάντας δὲ τοὺς πίθους ἐπὶ τὸν τροχὸν ἀναβιβάζουσιν οἱ κεραμεῖς, ἀλλὰ τοὺς μικρούς. τοὺς μέντοι μείζους χαμαὶ κειμένους ὁσημέραι ἐν θερμῷ οἰκήματι ἐποικοδομοῦσι, καὶ μεγάλους ποιοῦσιν.
Pollux, Onomasticon, VII, 164.
164. That around which those who make pithoi put the clay and shape it—this wooden core is called κάναβος.
164. Περὶ δὲ ὃ οἱ τοὺς πίθους πλάττοντες τὸν πηλὸν περιτιθέντες πλάττουσι, τοῦτο τὸ ξυλήφιον κάναβος καλεῖται.