The Wheel of Fortune was one of the favorite subjects of art and song in the Middle Ages. On a large square of white marble set in the pavement of the nave of the Cathedral at Siena, is the representation of a revolving wheel. Three boys are climbing and clinging at the sides and below; above is a dignified figure with a stern countenance, holding the sceptre and ball. At the four corners are inscriptions from Seneca, Euripides, Aristotle, and Epictetus. The same symbol may be seen also in the wheel-of-fortune windows of many churches; as, for example, that of San Zcno at Verona. See Knight, Ecclesiastical Architecture , II plates V , VI .