Restoration of the Sistine Chapel frescoes smoke and exhaust fumes of the city, being "much dirtier than the ceiling proper". The building was a little unstable and had already shifted considerably prior to Michelangelo's work of 1508, causing cracking of the ceiling, the crack in the "Judith" pendentive being so large that it had to be filled with bricks and mortar before painting. The upper part of the ceiling provided Michelangelo an irregular surface due to cracks and water seepage. Continued ingress of water from the roof and from unroofed exterior walkways above the ceiling level had caused seepage which carried down salts from the building
Sistine Chapel been written, the most famous piece being Gregorio Allegri's "Miserere". One of the functions of the Sistine Chapel is as a venue for the election of each successive pope in a conclave of the College of Cardinals. On the occasion of a conclave, a chimney is installed in the roof of the chapel, from which smoke arises as a signal. If white smoke appears, created by burning the ballots of the election, a new Pope has been elected. If a candidate receives less than a two-thirds vote, the cardinals send up black smoke — created by burning the ballots along