Brunelleschi’s Dome in Florence
Until 1418 the Cathedral of Florence was standing with an empty hole above the main altar location. After more than 200 years of construction the dome was not built yet. Nobody until 1418 had figured out how to build a dome with a diameter of 45 meters above 55 m high walls.
In 1418 the authorities published a context to plan the dome.the prize was 200 florins and eternal glory. A short, ugly, gruesome goldsmith, Filippo Brunelleschi proposed a double concentric dome wrapped by stone, iron and wood rings running all around the external brick shell to support circumferential stress as around an oak barrel.
He just came back from Rome where he studied Ancient architecture. He won the context in 1420 but the authorities wanted to flank him with another goldsmith and architect: Lorenzo Ghiberti so they would control each other. The two were rivals since Ghiberti won the context for the baptistery bronze doors few years before and Brunelleschi lost it. At that time Ghiberti was the most famous artist in Florence and very close to politicians.Brunelleschi was forced to work with him. Both received the same annual pay of 36 florins. In 1423 Brunelleschi’s only pay was raised to 100 florins for being the creator of the dome project. Some biographers report the story of Brunelleschi faking being sick and being away from the works for some time to show that Ghiberti was not able to do the job on his own and to prove he was the only person that could finish it. According to them this pushed the authorities to raise Brunelleschi’s wage and to get rid of Ghiberti.
The dome was growing at a rhythm of 30 cm a month.The round renaissance shape of the dome compared to the gothich structures of the Duomo in Milan symbolised the indipendence of Florence from the other city. The first technical problem to solve was how to lift the heavy blocks of sand stone up to the dome level . He invented a special machine with two oxes pulling and a special rope 183 meters long and 450 kg heavy tailor-made by the naval workers in Pisa. He also invented a 20 m high crane to move the blocks horizontally.
The bricks in the dome follow a haring-bone pattern. He often created models in wax or cutting a turnip for making his workers understand what they had to do. He also ordered to water down their wine to keep them bright. Brunelleschi started off as watchmaker but became also a sculptor, a painter and an engineer. He did not use scaffolding rising from the ground but instead he used a movable one that were supported by the dome base itself, making the city save lots of money for the wood. The dome was inaugurated by Pope Eugene IV on March 25 1436, the day of the Annunciation.
Ten years later another team started to build the lantern. In order to reach the lantern you have to climb 463 steps. Brunelleschi died on April 15 1446 by a sudden disease. He was then entombed in the Duomo Crypt below his dome. In the Anconella park in Florence there is a model of the dome in scale 1:5 made in 1987 by professor Massimo Ricci.