Brunelleschi’s Cupola, dome in English, of the cathedral is the largest masonry dome ever built, a miracle of design and engineering.
Inside it is 45,5 meters wide, while externally it is 54,8 meters wide, but you may not know that the dome actually is not a dome! Filippo Brunelleschi was famous for his jokes, he made fun of everybody and probably this is one of his joke.
The recurring question about the dome is: how is it possible that it doesn’t collapse?
Experts from all over the world have been studying and debating about it, trying to find an explanation to its construction and find out the secrets about it.
Actually the structure rests on a drum not on the roof itself, so it could be built without the need for scaffolding from the ground. Besides the two shells of the dome are supported by ribbed reinforcements and are joined by horizontal and vertical struts through which the staircase weaves lead to the top of the structure.
The total height of the cathedral is of 116.50 meters, the lantern is 21 meters high, the drum is 13 meters high and finally the height of the dome is 34 meters. There are 463 steps leading to the upper gallery, from where it is possible to admire the cycle of frescoes, covering a surface of 3600 square meters, representing The Last Judgment, the same subject which decorates the Baptistery.
Giorgio Vasari, who really admired Michelangelo, drew inspiration from the frescoes of the Sistina Chapel in Rome. Unfortunately he died on 27th June 1574 , before he could finish the whole work, which was completed by Federico Zuccari. Zuccari, who started to work on it two years after Vasari’s death, abandoned the fresco technique and he didn’t use the range of colours employed by Vasari
The gilded bronze ball, weighing 1900 kilograms, was realized by Verrocchio around 1470 and it was placed, together with the cross, at the top of the Cathedral on 27th May 1471. During the night between 26th and 27th January 1601, a lighting struck the large ball, which rolled down, with a part of the lantern and the dome and hit the square below with an enormous blow.
One year later the ball was placed on the top of the Cathedral again and large marble plate was placed on the exact spot of the square hit by the ball, behind the Cathedral, on the side of Via dell’Oriuolo, to remember the event.
Even if it is not easy to see, the balustrade located at the external base of the dome is unfinished. We know that at the beginning of 1500 the Opera of Santa Maria del Fiore made a competition, in order to find the architect to build it.
Among the competitors there was Michelangelo, but it was chosen the project presented by Simone del Pollaiolo, also called il Cronaca, Giuliano da Sangallo and Baccio d’Agnolo. The works started in 1512 but they were interrupted in 1515, when just one section was finished. Michelangelo was then in town and it is told that when it was asked his opinion about it, he said: “it looks like a cricket cage to me!”. Baccio d’Agnolo was so offended by these words, that he abandoned the project, which was never finished.