How Delia Quercia treated the "Sacrifice of Isaac" we do not know. His bas-reliefs upon the façade of S. Petronio at Bologna, and round the font of S. John's Chapel in the cathedral of Siena, enable us, however, to compare his style with that of Ghiberti in the handling of a subject common to both, the "Creation of Eve."[82] There is no doubt but that Della Quercia was a formidable rival. Had the gates of the Baptistery been entrusted to his execution, we might have possessed a masterpiece of more heroic style. While smoothness and an almost voluptuous suavity of outline distinguish Ghiberti's naked Eve, gliding upheld by angels from the side of Adam at her Maker's bidding, Della Quercia's group, by the concentration of robust and rugged power, anticipates the style of Michael Angelo. Ghiberti treats the subject pictorially, placing his figures in a landscape, and lavishing attendant angels. Della Quercia, in obedience to the stricter laws of sculpture, restrains his composition to the three chief persons, and brings them into close connection. While Adam reclines asleep in a beautiful and highly studied attitude, Eve has just stepped forth behind him, and God stands robed in massive drapery, raising His hand as though to draw her into life. There is, perhaps, an excess of dramatic action in the lifted right leg of Eve, and too much of pantomimic language in the expressive hands of Eve and her Creator. The robe, again, in its voluminous and snaky coils, and the triangular nimbus of the Deity, convey an effect of heaviness rather than of majesty. Yet we feel, while studying this composition, that it is a noble and original attempt, falling but little short of supreme accomplishment. Without this antecedent sketch, Michael Angelo might not have matured the most complete of all his designs in the Sistine Chapel. The similarity between Delia Quercia's bas-relief and Buonarroti's fresco of Eve is incontestable. The young Florentine, while an exile in Bologna, and engaged upon the shrine of S. Dominic, must have spent hours of study before the sculptures of S. Petronio; so that this seed of Della Quercia's sowing bore after many years the fruit of world-renowned achievement in Rome. Two other memorable works of Della Quercia must be parenthetically mentioned. These are the Fonte Gaja on the public square of Siena, now unhappily restored, and the portrait of Ilaria del Carretto on her tomb in the cathedral of Lucca. The latter has long been dear to English students of Italian art through words inimitable for their strength of sympathetic criticism.[83]