For centuries, the physical and spiritual center of Florence has been the Basilica di Santa Maria del Fiore, better known simply as the Duomo. Centuries in the building, the Duomo is the result of the work of an incredible number of hands and minds, and contains treasures, and represents history, of incalculable value. Today we’ll look at just one of its many remarkable features: the clock that stands over the main entrance to the cathedral.
The Duomo (the word means “cathedral” and of course in Florence, it’s always understood to refer to the Basilica di Santa Maria del Fiore) has an extremely long history. Though construction of the Duomo began in 1296, there has been a church on the site since at least the 5th century; the Duomo replaced an earlier cathedral. The Duomo is part of a complex that includes the cathedral itself, the campanile (bell tower) to the right in the above picture, which was designed by Giotto and which is nearly 280 feet tall, and the Baptistery, whose doors are across the piazza from the Duomo’s entrance. The Baptistery is the oldest of the three buildings and it’s conjectured the site was originally that of a Roman guard tower (Florence began as a small Etruscan town in around 200 BCE, which was razed by the Romans in 80 BCE; the Roman settlement of Florentia was established by Julius Caesar shortly thereafter as a kind of retirement community for veterans).
The Duomo is of course famous for its enormous dome, which was designed by the most famous of Renaissance architects, Filippo Brunelleschi, who had to invent a number of techniques and machines to construct it. It’s the largest brick dome ever made, even today, and had to be built without a temporary wooden inner framework (which would have been the preferred method) because there wasn’t enough local lumber to build one. You can easily spot it from the air, near the banks of the Arno River, as you come in on final approach to Florence Airport. The Duomo, like most large cathedrals, has a warren of hidden passageways created to allow inspection and maintenance of the huge structure. It required not decades, but centuries, to build; begun in 1296, it wasn’t really completed until 1887, when the current faÃ§ade was finally finished. The process took so long that the original Gothic faÃ§ade became an anachronism, and had to be torn down and replaced (sculptures from the original faÃ§ade are now housed in a museum behind the Duomo).
For a first time visitor to Florence the Duomo is overwhelming. The colored exterior (made of three different varieties of local marble, whose colors symbolize the virtues of Faith, Hope, and Charity) is dazzling, and the sheer scale seems intended to not only emphasize the spiritual authority of the church, but also its temporal power. Even to modern eyes, the Duomo is breathtaking and one can only imagine what sort of impression it must have made to Gothic or Renaissance eyes seeing it for the first time. As our tour guide (who earned her PhD. in Medieval art and architecture and who does tours of Florence because “in Italy, if you are an academic you had better be able to live on one salad a day”) said to us, the Duomo is not just a church, it’s also “the business card of the city of Florence.”
Like the Duomo, the clock has a very long history, and like Florence it has certainly had its ups and downs. The dial of the clock, painted by Paolo Uccello in 1433, is almost seven meters across; the original mechanism was finished in 1443 and was made by the clockmaker Angelo di NiccolÃ². There’s very little information about the original movement, but it seems very probable that a verge escapement was used (the only one known at the time). The clock, as you can see, had a 24-hour dial, and the single massive hand turns counterclockwise, once per day. The four figures at each corner are rather enigmatic. They may represent the four evangelists, but the earliest extant reference to them is in the famous Renaissance artist’s biographer Vasari’s Lives Of The Artists, and he simply refers to them as “four heads in the corners, painted in fresco.” The Evangelists is a good guess, but whether that’s what Uccello had in mind is a bit of a mystery. (The Lives was published in its first edition in 1550, 117 years after Uccello finished his work.)
In the so-called Italic system of timekeeping, which this clock is based on, the 24th hour of the day wasn’t midnight, but rather sunset, and the time for ringing the bells in the campanile adjacent to the Duomo was determined by the clock; at sundown the bells would toll to inform all that they should be within the city gates, which were locked after dark. The clock has had its mechanism replaced and upgraded on several occasions (notably, the original escapement was replaced with a pendulum mechanism in 1688) and the movement still in use today was made by the Florentine clockmaker Giuseppe Borgiacchi, in 1761. At that time, the clock was updated to a 12-hour dial, but 40 years ago a restoration returned the mechanism to its original time-telling format, which requires the clock’s current keepers, Lucio Bigi and Mario Mureddu, to keep up the ancient tradition of re-setting the hand once a week so that it always shows sundown at the correct time. The most recent restoration, completed in 2014, and sponsored by Officine Panerai, involved extensive cleaning and refurbishing of the mechanism to ensure its accurate and smooth operation, and guarantee its longevity.
Though most visitors to the Duomo snake through the nave in an enormous line that starts to form early each morning, it’s possible to actually go inside the walls of the Duomo and up a narrow spiral stone staircase, and see the room that’s housed the movement of the clock since the mid-1400s.
It would be easy to miss if you didn’t know it was there, but just before you exit the cathedral, there’s a small wooden door on the left, access to which is blocked by, of all things, a large wooden wastebasket. Our guide shifted this aside and then unlocked the door’s iron lock.
You go up the rough steps, following in the footsteps of almost 600 years’ worth of horologists (and occasional curious tourists, like ourselves) and finally, you reach a narrow corridor running between the inner and outer walls of the Duomo (the staircase is inside one of the pillars in the building’s faÃ§ade).
After the huge space of the Duomo’s interior (whose ceilings seem high enough you wouldn’t be surprised if an occasional cloud passed overhead) the chamber housing the movement seems tiny by contrast. The room smells faintly of old, damp stone, and machine oil. The movement is housed in an iron frame above a wooden platform you stand on to service it, or to rewind the driving weight; it’s held in place by rods set directly into the masonry.
The frame holding the movement is held together by big iron cotter pins, not screws, and it’s very simple: there is a wooden rod around which is wrapped the rope holding the stone weight that keeps the whole thing running; there’s the escapement itself (a fairly simple anchor escapement) and, of course, there’s the gear train that translates the slow release of the weight by the escapement into the movement of the hand.
The big crank on the left is for re-winding the rope holding the weight that keeps the clock running, and just above its shaft, you can see a duplicate of the clock’s dial. In this picture the exterior of the Duomo is on the left, and the interior on the right.
The dial is there in order to make it easier to tell where the actual hand of the clock is, in order to make it easier to perform the regular task of resetting the clock so as to keep the single hand coordinated with sunrise and sunset. Â You can also see the suspension for the pendulum and the crutch â a two pronged fork in between whose tines the pendulum swings. As it swings, it pushes the crutch back and forth, causing the anchor to lock and unlock the teeth of the escape wheel.
Below, you can see the inner wall of the Duomo, with the opening through which runs the shaft holding the actual hand.
Above, you can see the escapement, which looks like a so-called deadbeat escapement. The deadbeat escapement was designed for use in precision pendulum clocks, and, as it was invented in the late 17th century, it would have been a natural choice for this movement, which was installed in 1761 and which has been running, more or less, ever since. It seems to me this clock would be susceptible to temperature changes as there’s no obvious mechanism for temperature compensation, but as it has only an hour hand and as it has to be reset weekly in any case, temperature compensation is probably unnecessary. Â
Below, you can see the pendulum itself; the rod extends through a hole in the floor on which the movement sits, and the pendulum swings back and forth in its own little chamber. I’m not sure what the opening below that is for â perhaps at one time, the clock had a longer pendulum.
If you shine a strong light in between the wooden stairs leading up to the platform the movement sits on, you can just make out the oval stone that acts as the driving weight for the clock.
Along the narrow corridor running between the walls of the Duomo, there is a recess with discarded or unused parts from previous incarnations of the movement, and there is also, in a smaller recess at head height, a guest book you can sign to show you’ve been there.
From the outside, there’s no sign of the secret stairway winding up to the clock (the clock is directly behind the relief carving of the Madonna, above the arch of the main doors). The staircase is inside the column that forms the right side of the doorway. It’s a fascinating and slightly eerie experience to mount the steps and see the movement, which slowly ticks away the hours in total darkness, enclosed by centuries-old masonry, its only means of communication with the outside world the giant hand making its daily round inside the church itself. Thanks to Panerai and the team of restorers at the Duomo, we can still see it doing what it has done for nearly 600 years, and remember when mastery of hours meant both master of spiritual, and of daily life â and, indeed, a time when there was no difference between the two.
A very big thank you to Officine Panerai for arranging access to the Duomo Clock movement chamber. Â
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