The Great Dome Essay

One of the biggest questions in archeology has been how the dome on top of the Cathedral of Santa Maria del Fiore was built. Scholars know who built it, but they don’t know the means of its creation. Filippo Brunelleschi was the man and mind behind the creation of the dome. The Cathedral of Santa Maria del Fiore has managed to raise several questions and curiosity amongst scholars. In the early 14th century a feud between Florence and other emerging cities began, each trying to beat the other with building bigger cathedrals.

Florentines didn’t like the look of gothic cathedrals, for inspiration for their dome, they looked at ancient Rome’s famous building that payed tribute to all of the gods, the Pantheon. A mural, years before the dome had been created, depicted what the committee had in mind for the cathedral. Before Brunelleschi persuade his path in architecture, he was a Goldsmith. In 1401, Cloth guild wanted for the Baptistery of Florence to have a second set of doors. , the Cloth set up a competition in order to find the best sculptor.

Out of seven people who entered the competition, two people made it to the final round. Lorenzo Ghiberti, and Filippo Brunelleschi each had to recreate the famous biblical story of the sacrifice of Isaac, with a limited amount of bronze, also the panel would have to be inside a quatrefoil. In the Biblical Story God demands for Abraham to sacrifice his one and only living son, Isaac. Abraham had gone for a very long time trying to have a child, so his son meant a lot to him, and now he has to obey God.

So Abraham then decides to perform the sacrifice by stabbing Isaac in the neck when an angel descends from the heavens to stop Abraham from killing Isaac, and give him a ram to sacrifice in his son’s place. Brunelleschi and Ghiberti made the panels, and Ghiberti won the challenge with his Sacrifice of Isaac, which was more gentile and subtle compared to his rival Brunelleschi, whose panel was more violent, and dramatic. After this loss, Brunelleschi disappeared for 15 years, to where scholars believe he spent his time studying Roman architecture.

For over a hundred years the Cathedral of Santa Maria del Fiore remained unfinished, the original planners of the cathedral had been extremely ambitious with what they wanted, but the technology at the time didn’t let them achieve the largest dome in the world. Cosimo de Medici decided to find the answers for the dome. They decided to patron Brunelleschi. The church authorities decided to offer a massive cash prize for a solution to the dome. Brunelleschi’s model was the only one that was free-standing and didn’t require any support.

Him being fearful that his ideas would be stolen, he decided to write them in code and refused to share his ideas for the plan. The church authorities demanded Brunelleschi to do some kind of demonstration. Brunelleschi then challenged them to stand an egg on its end, after each of the authorities failed, Brunelleschi broke the bottom of the egg, and it stood up. The men complained saying that they could have done that, that the solution was so obvious. Brunelleschi proclaimed of course it was, and that so would the answer to the dome if he shared his plans. The Authorities gave him the commission for the dome.

When the construction of the dome started, Brunelleschi came with fresh ideas. Brunelleschi wanted his workers eating up on the dome, because he didn’t want them to go down and then back up again and be exhausted because of the distance they would have to travel going up of 350-400 odd stairs. He would give them wine, because it was safer than water. Brunelleschi would make sure that their wine would be diluted with 1/3 of water, which was the drink that pregnant women at the time would take. Up until Brunelleschi’s time, lifting devices were referred to as the Great Wheel.

Which was a giant wheel made out of wood, in which a human would walk inside causing the wheel to revolve, it would pull a rope, and that pull would then gradually lift the objet. Brunelleschi knew that the old method could not be used in the construction of the dome, because of the massive scale of the project. He then goes and invents something to solve the problem of lifting up the objects. He creates a hoist that uses oxen, instead of people, to raise and lower the materials. By inventing the hoist, he also invented the very first reverse gear in history. Making the oxen walk in the same direction saved precious time.

The hoists raises or lowers the materials depending on which of two horizontal wheels locks to a vertical wheel that is connected to the drum that has the rope coiled around it. When materials need to be lifted, the bottom wheel locks to the vertical wheel, and when the load needs to go down, the top wheel engages and turns the drum in the opposite direction. Up until that moment of time, no one had ever done that, he had solved the problem of lifting and lowering nearly 40,000 tons of material. The dome on top of the Cathedral of Santa Maria del Fiore has triggered the curiosity of scholars.

The mystery behind how Brunelleschi managed to build the dome without any support. The success of the dome had the odds against it, but Brunelleschi managed to build it and blew the minds of many. Brunelleschi undertook a project that he knew would be challenging and didn’t have the technology to complete. What seemed to be a single dome, is actually two domes, one inside of the other. One of Brunelleschi’s secretes to the success of the dome is that instead of building eight individual walls, he built a consecutive spiral wall that contains several ribs for structure and support.

Five years into the construction of the dome, the bricks started curving inwards, without a wooden framework to hold the weight, the project entered a dangerous stage. Most walls are built by laying bricks on straight lines. Because the walls were curving in, Brunelleschi had to change the brick laying pattern due to the weakness of the mortar compared to the brick. Gravity pulls the wall inward and so a crack could appear in one of the layers of the mortar, and the wall would collapse.

Brunelleschi’s new brick laying design was composed of bricks laying down horizontally and then are interrupted by vertical bricks, instead of the bricks being set down horizontally, they are in a zig zag pattern. This patter is called spina pesca, or herringbone. The bricks from the spina pesca pattern slope down making an inverted arch, one of the most stable forms in architecture. The combination of the spina pesca and the inverted arches keep the bricks in place redirecting the weight of the wall downwards, preventing them from collapsing.

Brunelleschi used a flower shape around the platform of the dome. The flower helps guide the construction of each wall. The flower works with rope lines. A worker was stationed at the bottom of the platform and would hook a line to the bottom of the flower and another worker at the top of the dome uses the other end of the rope. The rope dictated the angle and the height of the bricks. The shape of the flower is important because as the platform worker moves the line around the flower, the rope is used to transfer the angle of the flower on to the wall creating the inverted arch.

The walls are strong, but for the dome to be a success, the walls need to meet at the top, a miscalculation that would have been repeated thousands of times would have ended up in a disaster. The lines of the rope would cross from wall to wall establishing the center point of the dome, before any of the rope lines would give a brick into place, it would first have to pass through the center point. Brick by brick the walls of the dome increase in size until they meet at the top, almost 300 feet up in the sky and then the dome is complete.