Nevertheless, having despatched the other drawings to the Pope, with the names of those who had done them, he sent that of Giotto also, relating the mode in which he had made his circle, without moving his arm and without compasses; from which the Pope, and such of the courtiers as were well versed in the subject, perceived how far Giotto surpassed all the other painters of his time. This incident, becoming known, gave rise to the proverb, still used in relation to people of dull wits⁠—

Tu sei piu tondo che l’O di Giotto ; the significance of which consists in the double meaning of the word ‘tondo,’ which is used in the Tuscan for slowness of intellect and heaviness of comprehension, as well as for an exact circle. The proverb has besides an interest from the circumstance which gave it birth.⁠ ⁠…