Sistine Chapel ceiling of the chapel, now closed, and those above the High Altar covered by the Last Judgement. Above each window is an arched shape, referred to as a lunette and above eight of the lunettes at the sides of the chapel are triangular "spandrels" filling the spaces between the side pendentives and the vault, the other eight lunettes each being below one of the corner pendentives. Michelangelo was commissioned to paint these areas as part of the work on the ceiling. The structures form visual bridges between the walls and the ceiling, and the figures which are painted on them are
Restoration of the Sistine Chapel frescoes have been predicted by previous restorers. One of the major dangers to the frescoes is automotive exhaust, and they are also vulnerable to the effects of the crowds of tourists that pass through the chapel every day, bringing with them heat, humidity, dust and bacteria (the latter of which can biodegrade paints and pigments). The clean plaster surfaces are more in danger from these destructive elements than they were when they were covered with a layer of smoky wax. Previously, the Sistine Chapel's only ventilation was from its windows in the upper level of the walls. To prevent exhaust fumes