Instantly recognizable, Florence's cathedral dome is a Renaissance masterpiece. But did you know that when the Cathedral ("duomo" in Italian)was dedicated to Santa Maria Fiore (Our Lady of the Flowers) in 1412, the roof was open to the sky? The priests and the worshippers were at the mercy of the weather and the pigeons for many years. No one had any idea how to build a dome large enough to cover the gaping hole.
There had never been a plan or even a design for the dome. In addition, there was the problem of "centering." Centering was the traditional wooden framework used to support a dome while it was being constructed. But, the dome needed for the cathedral would have to have a span of some 140 feet--a whole forest of wooden beams would be required, and it was unlikely that any timber could be found that would be long enough or strong enough to do the job.
So, in 1420, a competition was held and experts from all over Italy came with suggestions of how the work might proceed. Most of the ideas were ludicrous and none seemed feasible. For instance, one idea was to bring in a huge mound of dirt, reaching to the opening, and adding to it as the dome was built. The mound would contain gold and silver coins. This way, the "expert" reasoned, the people of Florence would be eager to help remove the gigantic pile in the hopes of finding the buried treasure...
Other ideas were not much better, until Filippo Brunelleschi (Broo-nel-LAY-ski), an artist and architect, stepped up. He claimed that he had a design that would only require scaffolding for the builders (and not huge supports for the structure). The others all laughed and dared him to show this "impossible" design. But Brunelleschi refused, saying that if he did, someone would steal his idea.
Instead, he offered an ingenious demonstration. He challenged the other architects to a contest, and asked the Opera del Duomo (the commissioners in charge of the project) to award the contract to whoever was able to stand an egg on its end on a flat piece of marble. No matter how hard they tried, no one could do this equally "impossible" feat. Then, Brunelleschi took the egg; he gently cracked its bottom and stood it upright.
All the others loudly protested that they, too, could have done the same. Brunelleschi laughed and said that was his point: if he showed his design, they would all know how to build the dome. He agreed to show the Opera del Duomo his plans in private, and they awarded him the commission.
His plan was essentially to build two domes, one inside the other. Both were built with interlocking brickwork called herringbone, which is self-supporting. This eliminated the need for centering. He also used stone posts and wooden beams to help hold the dome together. Between each of its eight sides, vertical stone ribs connected the inner and outer domes. He built stairways and passages in between the domes to allow the workers easy access and for future repairs. He invented a kind of donkey-powered hoist to raise heavy materials. He even put in kitchens and makeshift privies to so builders wouldn't have to climb all the way down and then back up several times a day.
It took only 16 years to complete the dome, but the lantern topping it all was not finished for anothe
r 25 years by which time Brunellschi had died.
Today you can see a statue of this genius gazing upward at his masterpiece in the Piazza el Duomo in Florence. You can also climb the 463 steps of the dome and see the marvelous herringbone construction and a great view of the city when you finally reach the top.
I'll make the climb with any willing members of our tours, and I'll tell about Brunelleschi's many other accomplishments on the way. We'll be posting the dates and prices for our April 2008 tour in the next few weeks at Time of Your Life Tours.
