Brunelleschis Dome (18 page)

The order was not executed within the time stipulated. Two months after the abortive journey Filippo was purchasing a 240-pound rope with which to salvage either the stricken vessel or her cargo — a humiliating spectacle that Giovanni da Prato must have contemplated with relish. How Filippo attempted to recover the load from the bed of the Arno is not known, but a sketch by Taccola shows two stone-laden barges being used to raise a sunken marble column. Such salvage operations exercised the ingenuity and imagination of a number of engineers during the fifteenth century, leading to several attempts to design diving suits. Both Taccola and Francesco di Giorgio invented various types of breathing apparatus and underwater masks, as well as inflatable bladders to raise and lower divers. These works bore fruit in 1446 when, in one of the most celebrated engineering feats of the century, Alberti raised part of the hull of one of Caligula’s ships from the bottom of Lake Nemi by using divers from Genoa.

Filippo, however, met with no such success on the Arno. Almost four and a half years later the Opera was still pressing him to fulfill his contract to bring the errant 100 tons of marble to Florence — still, optimistically enough, on
Il Badalone
, which must have survived the wreck. In March 1433 Battista d’Antonio was forced to resort to the old and unsatisfactory expedient of cutting up tomb slabs for use on the dome. And that summer the Opera finally lost faith in Filippo and his wayward vessel, negotiating instead with three other contractors, who promised to deliver 600 tons of marble to Florence at a cost of 7 lire 10 soldi per ton — almost double Filippo’s proposed price.

Filippo had built
Il Badalone
and contracted for the load of marble entirely out of his own pocket. Altogether he lost 1,000 florins on the venture — the equivalent of ten years of his salary as
capomaestro
and roughly one-third of his total wealth. It must have been a cruel blow for a man who had envisioned reaping lucrative financial rewards from his invention. Even worse, his reputation as the modern Archimedes was tarnished — and would be undermined still further a few years later, when another of his clever plans was to rebound disastrously.

A
FEW WEEKS BEFORE
Il Badalone
weighed anchor, Filippo had ridden on horseback into the nearby hills to oversee the extraction of yet more sandstone from the Trassinaia quarry. The dome had by this time reached a height of over 100 feet, meaning that the teams of masons were now working 270 feet above the ground, or the equivalent of 20 stories in the air. As the shells curved ever inward, the masons began preparing to install the third of the sandstone chains. The beams started arriving in the Piazza del Duomo at the beginning of 1429. In preparation for laying them, Filippo’s
castello
was refurbished with a new set of pulley wheels.

Despite the embarrassing catastrophe of
Il Badalone
, the Opera del Duomo still displayed confidence in Filippo’s inventions and designs. The
rota magna
, the old treadmill built in 1396, was decommissioned and sold, having been rendered obsolete by the powerful new ox-hoist. Also sold was the timber used for the centering of the vaults in the tribunes. This latter act in particular revealed just how much faith Filippo inspired in the wardens. Deeply skeptical of his plans a decade earlier, they were now clearly convinced that the cupola could be raised without the use of a wooden centering. The evidence was, after all, right before their eyes in the shape of the half-finished dome. In fact, so confident had they become that Neri di Fioravanti’s 1367 model of the cathedral, once so sacred, now served the Opera as a lavatory.

Work on the third sandstone chain did not proceed quite as expected, however, and it would not be completed for another four years. The dome project was about to encounter its first serious delay. Construction first began to slow down when, in the summer of 1429, cracks were discovered in the side walls at the east end of the nave — that is, the end of the nave nearest the dome. Barely a year after the failure of
Il Badalone
, Filippo suddenly found himself faced with a potentially more serious disaster. It seemed that the church, as constructed, might simply be unable to support the heavy load of the dome.

There were no immediate signs of panic in the Opera del Duomo. Filippo was consulted by the wardens and, bold as ever, put forth one of his typically audacious proposals: he viewed the cracking walls as an opportunity to remodel the entire cathedral. What he now envisioned was a building different from the 1367 model but one that imitated another of Neri di Fioravanti’s designs instead: that of Santa Trìnita, the Gothic church beside the Arno that had been reconstructed by Neri on the site of a much older structure. Following Neri’s design, Filippo proposed to flank the side aisles of the cathedral with a series of chapels.

Filippo had already built or planned a number of such chapels in various of Florence’s churches, including the Barbadori Chapel in Santa Felìcita and the Ridolfi Chapel in San Jacopo. And in 1428 he had begun rebuilding the Augustinian church of Santo Spirito, which he planned to encircle with no fewer than thirty-six chapels, each belonging to a different family. It was the tradition in Florence for the bones of the wealthy to reside in splendor in special chapels within the churches (while those of Florence’s poor were piled in the charnel house). The remains of the Medici family lie in San Lorenzo, the Pazzi’s in Santa Croce. In fact, Florence’s churches were so crammed with tombs that during the fifteenth century one bishop voiced concerns about so many corpses defiling the House of God. His worries might also have been justified on the grounds of public health: in times of plague the houses nearest the churches were always the first to become infected.

The chapels that Filippo was proposing for Santa Maria del Fiore would do more than serve as repositories for the bodies of Florence’s finest citizens: they would form what he called a
catena totius ecclesie
, a “chain around the church.” Like the flying buttresses on the sides of Gothic cathedrals, they were to serve as abutments, bracing the walls of the nave against the outward thrust caused by the weight of the dome. Filippo assured the wardens that Santa Maria del Fiore would also be made much more beautiful as a result.

In September 1429 Filippo was ordered to begin work on a model. The wardens were interested not only in how the chapels might stabilize the cathedral but also how they could be incorporated into its existing structure, the external walls of which were already encrusted with marble and decorated with sculpture. Would all of this painstaking artistry have to be refurbished or removed? And at what expense to the Wool Guild? Work had barely begun on this new model, however, when another distraction arose. In November 1429 Florentine mercenaries attacked Lucca, the wooland silk-weaving city 40 miles to the west. It was to be an unexpectedly long and damaging campaign.

For so long prey to both plagues and wars, Florence had enjoyed a brief respite for the first few years of the dome’s construction. A war with the Kingdom of Naples had ended in 1414 when, in one of those miraculous events to which the Florentines were becoming accustomed, an earthquake shattered Naples and the enemy warlord King Ladislaus died of a fever. For the next ten years Florence experienced a period of peace, but then in the summer of 1424 Florence went to war once again. This time the enemy was the new duke of Milan, Filippo Maria Visconti.

Filippo Maria was as formidable a foe as his late father, that ruthless enemy of Florence, Giangaleazzo. And he was demented even by the standards of the Visconti family. Terrified of thunder, he would cower in a soundproof room during storms, while in better weather he enjoyed rolling naked in the grass. Gluttonous and obese, he was unable to mount a horse or even walk unaided, and so sensitive was he about his ugliness that he refused to have his portrait painted. His second wife was imprisoned after the duke, a superstitious man, heard a dog howl on their wedding night. Her fate was preferable, however, to that of his first bride, who had been beheaded.

Filippo Maria picked up where his late father had left off: in 1422 his troops captured both Brescia and Genoa, and a year later they seized the town of Forlì, only 50 miles from Florence. The following year, as plague raged through Tuscany, his forces defeated the Florentines at Zagonara, in Romagna. There were only three casualties, all Florentine soldiers who fell from their horses and drowned on the battlefield in their heavy plate armor (it had rained heavily in Zagonara the night before). This lack of bloodshed shows that warfare in the Middle Ages and Renaissance, contrary to popular conceptions, could be reasonably civilized. Most battles resembled chess matches in which opposing commanders sought to outmaneuver each other, the loser being the one who conceded that his position was technically vulnerable. These engagements were fought by mercenaries who settled the terms of warfare in advance, rather like sportsmen deciding the rules of a game. As a notary for the Commune, Filippo’s father had frequently been involved in these negotiations, traveling far afield to engage the services of mercenaries such as the Englishman Sir John Hawkwood, who had commanded the Florentine army between 1377 and 1394. By common agreement the armies declined to fight in certain conditions: at night, in winter, on steep slopes, or on boggy ground. The engagements were not always quite so congenial, however: six months after Zagonara, the Florentines lost an entire army against the Milanese at Valdilamone.

The battles against Lucca were even more disastrous. A truce had been signed with Filippo Maria in April 1428, when to celebrate the occasion, torches were burned on the walls of Santa Maria del Fiore. But the ink was barely dry on the treaty when the Florentines set their sights on their neighbor. Like many medieval cities, Lucca had suffered a checkered past, passing from the hands of one warring state to another. In the previous hundred years it had been occupied by the Bavarians, sold to the Genoese, seized by the king of Bohemia, pawned to Parma, ceded to Verona, and finally sold to Florence. Now war was advanced by the Florentines on the pretext that Lucca’s ruler, Paolo Guinigi, had secretly been supporting the duke of Milan. The campaign went badly from the outset, with the Republic soon getting bogged down in an unsuccessful war against a smaller and weaker foe. After several months of stalemate the Dieci della Balìa (the War Office) decided to unleash their secret weapon: in March 1430 Filippo Brunelleschi was sent into the field.

It was by no means unusual for an architect to become involved in a military campaign during the Middle Ages. Besides the cathedral in Florence, the Opera del Duomo was responsible for all military architecture within the Florentine domains. The men who built Santa Maria del Fiore were therefore the same ones who fortified Florence and its neighbors with walls, moats, and bastions. Some ten years before starting work on the foundations of the new cathedral, Arnolfo di Cambio began raising a set of defensive walls around Florence. These massive fortifications were completed by Giotto in the 1330s. Two centuries later Michelangelo would rebuild these walls, raising bastions around San Miniato with unbaked bricks made from hemp and dung. And Leonardo da Vinci was forever drawing plans for weapons of war, including scythed chariots, steam cannons, and gigantic crossbows.

Like Arnolfo di Cambio and Giotto, Filippo was expected to carry out military commissions as a regular part of his duties. It was a busy time to hold the post of
capomaestro
, for during the 1420s towns throughout Tuscany were being buttressed as protection against the mortars and siege engines of the Milanese. Filippo was involved in fortifying Pistoia as early as 1423, and a year later he began work at Malmantile, a stronghold in the Arno Valley between Florence and Pisa. This fortress was completed two years later, when parapets, battlements, towers, and a moat were in place. Unlike many of Filippo’s other architectural commissions, this stronghold was of a fairly traditional design. It operated on the time-honored principle that any assailants who survived the hail of arrows fired from crossbows along the walls, and then managed to traverse the moat, would be crushed to death by large stones dropped from the parapets.

These were all defensive maneuvers, however. What was required in 1430 was an offensive weapon — some means of subduing the stubborn Lucchese once and for all. Mortars were being fired at Lucca from a distance of 1,200 feet, and the city’s walls had been badly damaged. But still the Lucchese failed to relent.

The technology of warfare was undergoing a transition during the fifteenth century. Gunpowder — seen by many as a devilish invention — had been introduced in the previous century, and large-caliber cannons were being cast, along with projectiles weighing several hundred pounds. However, since the formula for gunpowder (a mixture of saltpeter, sulfur, and charcoal) had yet to be perfected, ancient and medieval devices such as siege engines, catapults, and battering rams were still in widespread use. Plans for both sorts of weapons are shown in a manuscript from the 1430s,
De Machinis
, written by Filippo’s friend Mariano Taccola. This treatise includes diagrams and descriptions of traditional devices such as articulated siege ladders and a bewildering array of catapults for hurling boulders at the enemy. There are also bombards and barrels filled with gunpowder and equipped with fuses. One of Taccola’s most celebrated designs involved exploding a keg of gunpowder in a tunnel excavated under an enemy stronghold (a ploy that would reemerge at the Battle of the Somme in 1916). No direct evidence exists of Filippo’s collaboration on these designs, but scholars have speculated that the
capomaestro
may have originated at least some of them.
¹
Certainly a number of the catapults — loaded by hoists and powered by counterweights — were well within Filippo’s widely recognized area of expertise. However, his plans for subduing Lucca involved something much more ambitious.