Focus on Sistine Chapel ceiling and explore the Architectural scheme.
The Sistine Chapel is about 35 m (118 ft) long and 14 m (46 ft) wide, with the ceiling rising to about 20 m (66 ft) above the main floor. The vault is of quite a complex design and it is unlikely that it was originally intended to have such elaborate decoration.
The chapel walls have three horizontal tiers with six windows in the upper tier down each side. There were also two windows at each end, but these have been closed up above the altar when Michelangelo's Last Judgment was painted, obliterating two lunettes. Between the windows are large pendentives which support the vault. Between the pendentives are triangularly shaped arches or spandrels cut into the vault above each window. Above the height of the pendentives, the ceiling slopes gently without much deviation from the horizontal.The first element in the scheme of painted architecture is a definition of the real architectural elements by accentuating the lines where spandrels and pendentives intersect with the curving vault. Michelangelo painted these as decorative courses that look like sculpted stone mouldings. These have two repeating motifs: the acorn and the scallop shell. The acorn is the symbol of the family of both Pope Sixtus IV, who built the chapel, and Julius II, who commissioned Michelangelo's work. The scallop shell is one of the symbols of the Madonna, to whose Assumption the chapel was dedicated in 1483. The crown of the wall then rises above the spandrels, to a strongly projecting painted cornice that runs right around the ceiling, separating the pictorial areas of the biblical scenes from the figures of prophets, sibyls, and ancestors, who literally and figuratively support the narratives. Ten broad painted cross-ribs of travertine cross the ceiling and divide it into alternately wide and narrow pictorial spaces, a grid that gives all the figures their defined place.A great number of small figures are integrated with the painted architecture, their purpose apparently purely decorative. These include pilasters with capitals supported by pairs of infant telamones, rams' skulls are placed at the apex of each spandrel like bucrania; bronze nude figures in varying poses, hiding in the shadows, propped between the spandrels and the ribs like animated bookends; and more putti, both clothed and unclothed, strike a variety of poses as they support the nameplates of the Prophets and Sibyls. Above the cornice and to either side of the smaller scenes are an array of medallions, or round shields. They are framed by a total of 20 more figures, the so-called ignudi, which are not part of the architecture but sit on plinths, their feet planted convincingly on the fictive cornice. Pictorially, the ignudi appear to occupy a space between the narrative spaces and the space of the chapel itself.
Last Judgment mould Sibyl vault Pope Sixtus IV Sistine Chapel lunette cornice fig ignudi angel altar pendentive nude travertine telamones ribs Prophet art spandrel bucrania Madonna mouldings plinth Michelangelo