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 ceiling various components of the ceiling are linked to this Christian doctrine. Traditionally, the Old Testament was perceived as a prefiguring of the New Testament. Many incidents and characters of the Old Testament were commonly understood as having a direct symbolic link to some particular aspect of the life of Jesus or to an important element of Christian doctrine or to a sacrament such as Baptism or the Eucharist. Jonah, for example, was readily recognisable by his attribute of the large fish and was commonly seen to symbolise Jesus' death and resurrection. While much of the symbolism of the ceiling dates