1932. And one morning going into the workshop of Giotto, who was at his labors, he showed him the mind of the Pope, and at last asked him to give him a little drawing to send to his Holiness. Giotto, who was a man of courteous manners, immediately took a sheet of paper, and with a pen dipped in red, fixing his arm firmly against his side to make a compass of it, with a turn of his hand he made a circle so perfect that it was a marvel to see it.
1933. Having done this, he turned smiling to the courtier and said, “Here is the drawing.” But the courier, thinking he was being laughed at, asked, “Am I to have no other drawing than this?” “This is enough and too much,” replied Giotto, “send it with the others and see if it will be understood.” The messenger, seeing that he could get nothing else, departed ill pleased, not doubting that he had been made a fool of.
1934. However, sending the other drawings to the Pope with the names of those who had made them, he sent also Giotto’s, relating how he had made the circle without moving his arm and without compasses, which when the Pope and many of his courtiers understood, they saw that Giotto must surpass greatly all the other painters of his time.
1935. This thing being told, there arose from it a proverb which is still used about men of coarse clay, “You are rounder than the O of Giotto," which proverb is not only good because of the occasion from which it sprang, but also still more for its significance, which consists in its ambiguity, tondo, “round,” meaning in Tuscany not only a perfect circle, but also slowness and heaviness of mind.