Only a very few of the first artists have been able to give an illusion of movement in the air by use of drapery alone, the device adopted by Michelangelo in the Sistine Chapel frescoes being perhaps the most effective. He throws behind the moving figure of the Deity a large fold of drapery, which assumes an oval or nearly round shape, the whole acting as a concave framework for the Deity and attending Angels.[a] The success of the plan arises of course from the apparent resistance to the air offered by a large and compact surface. This form with more or less marked modifications in the concavity was probably used by the ancient Greeks in their paintings, as a nearly similar arrangement is found in a sculptured figure which has come down to us, though in this case a running movement is indicated.[b] It is also seen in some Pompeian frescoes, where it is applied to figures moving through the air and on the ground.[c] Raphael adopted the device occasionally,[d] but generally varied it with excellent effect by flowing out from the waist a large scarf-like fold to take a circular form above the head and shoulders of the figure,[e] or by causing heavy drapery to flow out from the lower part of the body.[f] No doubt in the case of Raphael, the extraordinary grace of figure, and the perfect pose of the limbs, assist the illusion. Tintoretto and other artists of the Renaissance used an oval drapery in a similar way; while sometimes the figure is half hidden within it,[g] and Le Sueur wrapped part of the figure in folds before forming the oval.[h] There seems to be a simple virtue in any oval form connected with figures presumed to be suspended in the air. It was quite common in the early days of the Renaissance for the Deity or Virgin and Child to be placed in a regular oval framework, sometimes supported by Angels or cherubs, and the illusion was usually successful.[i] Rubens by way of experiment went a little further in one picture, for he placed the Virgin and Child in an oval picture frame supported by cherubs.[j] This however does not seem so novel as some of Perugino's ovals which are bordered with the heads of cherubs.[k] [a] See Plate 24. [b] The Son of Niobe, Uffizi Gallery, Florence.[72] [c] Herculanum et Pompei, vol. iv., by Roux Ainé. [d] Ceiling of the Hall of Heliodorus, Vatican. [e] Vatican frescoes God Separating Water and Earth, and God Appearing to Isaac. [f] The Creation of the Sun and Moon. [g] Poussin's St. Francis Zavier, Louvre. [h] The Virgin appearing to St. Martin. [i] See the Assumption of Orcagna, and of Luca di Tome; Giunto Pisano's Christ and the Virgin; and Mainardi's Madonna giving her Girdle to St. Thomas. [j] Virgin and Child, Chiesa Nuovo, Rome. [k] Ascension of Christ, Perugia; Assumption, Florence Academy, and others.