The magnificent church towers over all the city. No matter where you are in Florence, all you have to do is look up, spot the dome, and you will know where you are. The Duomo in Florence is one of the most impressive feats of architectural skill in the Renaissance world. (Incidentally, “duomo” does not mean “dome” in Italian. It is from the Latin “domo” meaning “house.” So, “duomo” in Italian means the house of God–it is the most common word for cathedral, the seat of the local bishop.)
By the 13th century Florence was becoming rich, due to the emerging banking industry there. Local wealthy businessmen wanted to show off their dedication to God, as well as their new-found wealth, and build a new impressive building in which to worship. The Duomo was begun in 1296, The nave (the main section of the church where worship is conducted) was not completed until 1418. The only part left to complete was a dome. But how to do it?
Everyone knew of and admired the poured concrete of the dome in the Roman Pantheon. However the technology to imitate that dome of the ancient Romans had been lost! So the Florentines had a competition between the two leading architects/artists of the day to build a new type of dome: Lorenzo Ghiberti and Filippo Bruneleschi. Both men were geniuses. Bruneleschi won. He created an octagonal dome within a dome (you can still walk up a long flight of stairs all the way to the top), The outer dome is entirely of brick, built without a temporary supporting frame. How in the world did they build this without the bricks just falling down and the whole structure caving in? How in the world did these people hoist 37,000 TONS of material (including 4 MILLION bricks) that high up?
(A humorous but true story is that bakers and chefs were brought up daily to feed the workers as they slowly and carefully laid the bricks in a herringbone pattern, with teams laying the bricks equally at the same time all around the dome so that the walls would be supported by their own pressure. Imagine a bakery being brought up each day to feed the hungry workers their lunch! The Italians are serious about their food and art. I think the two go together. The dome was finally completed in 1436.)
We know some of the techniques, and we know about some of the machines built to hoist the material all the way up, but many of the engineering techniques of the architect and construction are lost to history, unfortunately. All we can do is stand on the piazza and gaze up in wonder at the massive pink, green, and white marble of the church and gasp at the beauty, or we can make the climb to the top of the dome and marvel at the beauty of Florence and thank God for the ingenuity and dedication of people from long ago.