Filippo Brunelleschi and "IL Duomo"

Filippo Brunelleschi (1377-1446) was one of the most important architects, engineers, and sculptors of the Italian Renaissance. His most famous structure is the Dome - Il Duomo - part of the Church Santa Maria del Flore, the Cathedral in Florence, Italy.
Brunelleschi was trained as a goldsmith and a sculptor in a workshop in Florence in 1392. Around this time he met Paolo dal Pozzo Toscanelli who became a mentor to young Filippo. Toscanelli was a merchant and medical doctor and he taught Filippo mathematics and science, especially the principles of geometry. He was also able to bring out Filippo's interest in technology.
In 1401, Brunelleschi entered a competition proposed by the Lord of Florence to design the bronze doors of the Florence Baptistry. Seven artists entered. Brunelleschi tied with Lorenzo Ghiberti, but the judges gave Ghiberti the commission, proposing that Brunelleschi act as his assistant. Filippo did not like this idea and withdrew. Both artist's panels can be seen in the Bargello Museum which is housed in the Palazzo del Bargello in Florence.
After this,Filippo turned to architecture. He was great friends with the sculptor Donatello and they spent several years in Rome studying . Brunelleschi immersed himself in the study of antiquity, especially Roman engineering - temples, buildings, baths, amphitheaters, paying particular attention to construction of architectural elements such as vaults and cupolas.
Brunelleschi also did work in mathematics. His most important work in that field was the rediscovery of the principles of linear perspective using mirrors. He did studies of the scale and computed the relation between actual length of an object and its length in the picture depending on its distance behind the plane of the canvas. Using these principles, he drew various scenes of Florence with correct perspective.
The Cathedral in Florence, Santa Maria del Fiore, had a partially completed dome. Work on the cathedral had begun in 1296 and over a hundred years later it was still not completed. The painter Giotto had worked on the building from 1334 until his death in 1337. Brunelleschi became interested in the dome - called Il Duomo - around 1409. The dome had posed a problem for architects for years and many had tried to find a solution. Part of the problem was that when the Cathedral was built no one knew how the dome could be constructed. It was to be larger than the Pantheon's dome in Rome and no dome of that size had been built since antiquity. And buttresses were forbidden by the city. The fact that the dome was to go over the octagonal Baptistry didn't help. Brunelleschi decided he was going to find the solution.
Since childhood, Filippo had been interested in mechanical things - clocks, wheels,, gears, and, especially, weights. In 1418 the wardens of works of the cathedral set up a competition to find a solution to the dome problem. Brunelleschi used his artistic and mathematical skills and his understanding of mechanics and came up with a proposal. His idea was to use brick as a building material, laid in rotating herringbone patterns. His methods included ways of lifting the materials into position, avoiding the use of scaffolding but including the use of machines, which he designed specifically for the project. Once again he was up against Ghiberti but this time he was the one given the commission (in 1420).
It was a long difficult project. Brunelleschi used more than 4 million bricks. He invented a new hoisting machine for raising the masonry needed for the dome. He issued one of the first patents for the hoist in order to prevent theft of his ideas and was granted the first modern patent for his invention of a river transport vessel.
By 1446 the Dome was nearly completed. The only thing left was to hang a huge lantern which was to hang from the center of the dome. This lantern was to help support the dome. But pundits said it wouldn't work and Brunelleschi was forced to take part in another competition before they would let him install it. Unfortunately he died(in 1446) before he could complete the job but it was finally finished according to Brunelleschi's specifications by his friend Michelozzo in 1461.
Il Duomo was the first octagonal dome in history to be built without a wooden supporting frame. At the time, it was the largest dome ever built; it still holds the title of largest masonry dome in the world. It weighs 37,000 tons and contains over 4 million bricks. The dome also used horizontal reinforcements of tension chains of stone and iron. Brunelleschi's dome paved the way to the future of iron and steel reinforcements, such as reinforced concrete in later centuries.
The facade of the cathedral was demolished in 1587-1588. It was not replaced until yet another competition was held in 1864 to design a new facade. The new facade was completed in 1876.
Brunelleschi worked on several other buildings, even as he was working on il Duomo. Among his other churches are Basilica di San Lorenzo di Firenze and Santo Spirito di Firenze

Giorgio Vasari was an artist, biographer, and contemporary of many of the great Renaissance artists. His Lives of the Artists is a classic. Click the link to read what Vasari had to say about Brunelleschi.