by Judith Anne Testa
A reading of the earliest biography of Brunelleschi, probably written in the 1480s by Antonio Manetti, leaves one with the impression that the author was as mystified as everyone else by the details of Brunelleschi's building methods. "Between the shells of the cupola," Manetti writes -- just as if he actually knew what he was talking about -- "both toward the inside of the church and on the tiled outside surface as well as [hidden] in its [shells], are diverse provisions and devices in various places. The hidden [devices] are much more numerous than the exposed: for protection against wind, earthquake, and its own weight -- which could be harmful [with respect] to what is below in a [particular] place, and more with respect to the things piled up above [in their relation] to the things below." Huh?
According to a story told by Manetti, the architect's passion for secrecy enabled him to take revenge on his perennial rival Ghiberti. In 1426, when work on the wood chain was about to begin, Brunelleschi took to his bed. Responsibility then fell to his co-capomaestro, Ghiberti, to oversee the construction of the chain, something he had no idea how to do. Work halted as Brunelleschi remained in bed, claiming to be on death's door, while masons grumbled and Ghiberti dithered. But as soon as Brunelleschi heard that Ghiberti had begun constructing and raising a portion of the chain, he made a miraculous recovery. He staged a dramatic arrival on the site, clambering up into the dome to inspect Ghiberti's work and pronouncing it worthless. He ordered it removed and replaced with construction completed under his personal supervision. The Operai responded by tripling his salary and dismissing Ghiberti. Although Brunelleschi's triumph seemed complete, Ghiberti was eventually hired back, probably at his own insistence, but with sharply reduced authority, responsibilities and salary.
The method by which Brunelleschi figured out how to regulate the gradual curvature of the dome and calculate the ever-increasing angles at which the stones, bricks, and massive stone beams were to be laid remains one of the dome's unsolved mysteries. Once the dome had reached the height of 70 feet above the drum, another crucial problem arose: the shells would now curve inward beyond the critical angle of 30 degrees, above which gravity and friction alone wouldn't keep the mortar in place until it hardened. Brunelleschi now switched from stone to brick to lessen the weight and designed wooden molds for specially shaped bricks, which were to be laid in interlocking herringbone patterns, also of Brunelleschi's design, but based on his studies of ancient Roman brickwork.
These were terrifying times for the masons, who now had to work on walls that leaned inward at an alarming angle almost 250 feet above the ground. Domes built with wood centering at least had a network of scaffolding to break falls and obscure the view of the abyss below. To calm his increasingly anxious masons, Brunelleschi designed a portable parapet to go around their narrow working platforms, less for safety than for screening the sheer drop. According to cathedral documents, the purpose was "to prevent the masons from looking down." Despite the perils, there was only one fatality during the construction of the dome.
Brunelleschi declared the dome complete in 1436, although much remained to be done, including the decoration of the raw masonry just above the drum (which was never fully carried out), the tiling of the exterior shell, and the design, construction, and installation of the lantern. Given Brunelleschi's extraordinary achievement, it seems incredible that the Operai insisted on yet another competition to design the lantern. Brunelleschi won that one, too. Although Brunelleschi's lantern seems small in relation to the bulk of the dome, it required more than a million pounds of stone to be raised to the top of the cupola. As huge blocks of marble, some of them weighing 5,000 pounds, began to pile up near the cathedral, nervous Florentines imagined their precious new dome collapsing under all that extra weight. But Brunelleschi dismissed their fears, noting that the lantern would strengthen rather than crush the dome, by acting as a common keystone for the arched ribs of the vault. Once again, he was right. No part of his dome has ever collapsed and it's never needed major repairs.
The great architect didn't live to see his lantern take form, although it was eventually built from his handsome, classically inspired designs. He witnessed the consecration of its first stone by the archbishop of Florence in March of 1446. When he died less than a month later, just short of 70 years old, he received the rare honor of being buried inside the cathedral. Although Brunelleschi never married, he had an adopted son and heir, Andrea Buggiano, who carved a memorial monument: a roundel containing Brunelleschi's portrait and an inscription, composed by the chancellor of the Republic of Florence, that loftily compares Brunelleschi to Daedalus, the fabled engineer of ancient Greek mythology, a reference that brings to mind the idea that the cathedral dome raised without centering was an achievement comparable to Daedalus's miraculous flight.
But Brunelleschi's actual floor tomb was so modest that its location was soon forgotten and it was only rediscovered during archeological work on the cathedral in 1972. The simple inscription on it reads: "Here lies the body of the great ingenious man Filippo Brunelleschi." An equally fine epitaph might be the words written by another eminent Florentine: the art theorist, scholar, and gentleman-architect Leonbattista Alberti. In dedicating one of his books on art to Brunelleschi in 1435, he praised the brilliant achievement of the cathedral dome: "Who would ever be so hard of heart or envious enough to fail to praise Filippo the architect on seeing here such a large structure, rising above the skies, ample to cover with its shadow all the Tuscan people?"
After more than half a millennium the dome still "rises above the skies," and is still the very signature of Florence, the city's most striking feature, visible from innumerable points within and around the city and in clear weather from as far away as Pistoia. Until the development of new kinds of ultra-strong building materials in the twentieth century, it remained unrivaled in size. Even Michelangelo's dome of St. Peter's, although taller, is 10 feet narrower; Wren's cupola for St. Paul's in London is smaller by 30 feet, and the dome of the United States Capitol in Washington, D.C., is less than two-thirds the size of Brunelleschi's creation. Brunelleschi's achievement has become so closely identified with the Florentines' sense of self that it remains a powerful symbol even today. In a still current expression, a citizen strongly dedicated to the city is called a "fiorentino di cupolone" -- a Florentine of the BIG dome.
Visitors can follow in the footsteps of Brunelleschi and his masons and climb to the top of the dome, although the ascent isn't for those unaccustomed to extended stair-climbing, made dizzy by heights, or rendered nervous by enclosed spaces. There are 463 steps to the summit. Imagine making the better part of that climb twice a day -- once up and once down -- as Brunelleschi's masons did six days a week for 16 years. Today's visitors begin their ascent via a spiral staircase in the southwestern pier, one of the four that supports the dome. The first 150 steps lead only to the top of the pier, where the visitor emerges onto an interior balcony that encloses the base of the dome. Nowhere does the vast span of the dome seem greater than from there.
From this balcony a small door leads into the gradually narrowing space between the two shells of the dome, where another set of steps, constructed along with the cupola, threads its way upward. Between the two tilting walls of the inner and outer shells is a confusing maze of low doorways, cramped passages and other, irregularly ascending staircases almost nightmarish in their complexity and seeming irrationality, but all of them had their functions and were used by the builders. Only from within these constricted spaces is it possible to see close-up the various devices and techniques employed by Brunelleschi. The great stone chains, the wood chain, and the complicated, whirling pattern of herringbone brickwork, are all visible. Small windows pierce the outer shell, letting in light and air and offering brief glimpses of the city.
A final set of steep steps scales the uppermost part of the dome and shallow iron steps lead out onto the viewing platform at the base of the marble lantern, as far as anyone is allowed to go. The climb rewards the visitor with unparalleled views of the city of Florence and the Tuscan countryside. It also has the effect of removing the feeling that the dome is a miraculous creation and replacing that impression with something better and more accurate: the realization that the great dome is the product of an extraordinary human mind brought into being by a remarkable team of workers. It was built by human hands, at enormous cost and with almost inconceivable effort, amid wars, plagues, and personal and political intrigues, with a relatively limited understanding of the properties of materials and how the forces of nature act on those materials. Not the least of the effects of a trip to the top of the dome is a renewed sense of awe for the skill and intellect of that "great ingenious man Filippo Brunelleschi."