I feel like I am in some sort of convergence around the topic of domes. Perhaps it is the thinning hair on the top of my head. I am always surprised when I stand in front of one of those three-way mirrors you find in stores to see that there is an embarrassing thinning going on just out of sight. The old saw, "out of sight, out of mind" never seemed more fitting.
But back to more real domes. This last weekend marked the 100th anniversary of the laying of the cornerstone of the Cathedral of St. Paul (Minnesota). The dome is 96 ft in diameter and 175 feet high. The architect for the cathedral was Emmanual Masqueray who was the chief architect for the 1904 World's Fair in St. Louis, MO. The Archbishop of the Immaculate Conception Parish of the Catholic Church in Minneapolis and St. Paul, John Ireland, had met Masqueray at the World's Fair and invited him to Minnesota to design not one but two large churches in the Twin Cities...at the same time. St. Paul was to have a cathedral and Minneapolis was to have a pro-cathedral to be named the Basilica of St. Mary. The Cathedral of St. Paul (pictured here) is a beautiful building perched on a hill in view of yet another domed building, the Minnesota State Capital (pictured here). Both of these St. Paul domes provide an impressive skyline that would be the envy of most cities.
Coincidental with this anniversary, I have been reading Ross King's fascinating book, Brunelleschi's Dome. The book describes the way in which Brunelleschi built the dome of the Santa Maria del Fiore in Florence. This was no trivial matter. In fact, when the dome was conceived in the mid-1300s the architect Neri di Fioravanti had no idea how to actually build the dome and left it in the hands of God to provide someone who could do it when the time came. That time was 1418 when Fillipo Brunelleschi won a competition to build the dome. The catch was that Fillipo was very secretive and did not disclose exactly how he planned to carry it off. What he did do was build a 12 foot high model of the dome that showed some of the points of construction. This, along with some accolades from other work he had done convinced the judges to give the commission to Brunelleschi. Just to hedge their bets, however, they also appointed the other leading entrant, Loerenzo Ghiberti, as the co-leader on the project (even though Lorenzo had no idea how to build such a structure).
Brunelleschi took his inspiration from the Pantheon in Rome. Built in 128 AD, the Pantheon still remains as the largest unreinforced solid concrete dome in the world (43. 4 meter in diameter, or 142.4 feet).
Brunelleschi took many design ideas from the Pantheon but the Duomo's dome was to be built from bricks and stone, not concrete (duomo is a generic Italian term for cathedral. It derives from the Latim "domo" meaning house). Brunelleschi conceived and built massive hoists and construction frameworks that allowed the structure to be built without any scaffolding connected to the ground. This was an unprecedented achievement. The dome (42 - 45 meters in diameter (137.8 - 147.6 feet) for it is octagonal, not round) was completed in 1436 and has withstood numerous earthquakes over the years without ever developing a crack. The structural engineering is nothing short of remarkable.
I would say that my hat's off to the designers of these great domes...except I keep my hat on as much as possible to shore up my own do(0)med vanity.
Pictures of Duomo, Pantheon, and Minnesota State Capital from Wikipedia