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
Restoration of the Sistine Chapel frescoes the summer and winter months so that changes to the atmospheric environment occur gradually. The air near the ceiling is kept at a temperate level, while the air in the lower section of the building is cooler and circulates more rapidly, with the effect that dirt particles fall towards the floor rather than being streamed upwards. Bacteria and chemical pollutants are filtered out. Environmental specifications: When the restoration of the Sistine Chapel was announced, it sparked a barrage of queries and objections from art historians around the world. One of the most vocal of these critics was James Beck, of