Da Vinci's Ghost (15 page)

Figure 22.
Domes and study for the head of St. James, by Leonardo da Vinci (c. 1495).

* * *

B
RUNELLESCHI SEEMS NOT
to have kept notebooks or put his engineering ideas onto paper. Instead, obsessed with guarding his secrets, he preferred to work with three-dimensional models and keep the details in his head. But other artist-engineers of his generation did sketch out their thoughts and designs, and in their work one finds a precedent for the notebooks that Leonardo would begin keeping in the early 1480s. The most influential of these figures was Mariano di Jacopo, a Sienese colleague and confidant of Brunelleschi, known in his day as Taccola (“the Crow”).

Taccola and Brunelleschi had much in common. Almost the same age, both men had started out as craftsmen: Brunelleschi as a goldsmith, Taccola as a wood-carver. Both had worked as sculptors and artists. Both had risen to prominence in their native cities as engineers and inventors with a special interest in public works, architecture, the lifting and moving of weights, the harnessing of water power, and the design of boats, aqueducts, and war machines. By the time they met, Brunelleschi’s fame as an architect and engineer extended far beyond Florence. Taccola, for his part, was known as the Sienese Archimedes, a reference to the ancient Greek mathematician and inventor Archimedes of Syracuse, who in the third century
B.C
. had invented a variety of pumps, water screws, siege engines, and other devices, a number of which Vitruvius would catalogue in the
Ten Books
.

Unlike Brunelleschi, however, Taccola sketched out scores of engineering designs and ideas, which survive today in two works. The first,
On Engines
, dates from the 1420s and 1430s;
the second,
On Machines
, dates from the 1440s. Both brim with idiosyncratic illustrations that are by turns practical and fanciful: a variety of winches, gears, levers, cranks, cranes, siphons, pumps, catapults, ladders, and mills; animal-powered aquatic vehicles, a sail-powered land vehicle, and an underwater breathing apparatus; an underground explosive mine; plans for constructing harbors and desalinating seawater. Taccola’s illustrations also include some of the earliest known drawings of the devices invented by Brunelleschi for the construction of his dome (
Figure 23
).

Figure 23.
A machine of Brunelleschi’s, as illustrated by Taccola. “It is built for [four] reasons,” its caption reads. “First, because it turns rapidly. Second, because it facilitates lifting as large weights are raised on high. Third, because it runs forward and not backward. Fourth, it does not waste time.”

Copies of Taccola’s manuscripts and illustrations circulated among artist-engineers in the latter half of the fifteenth century. Given his interests, Leonardo is likely to have sought them out in either Florence or Milan, and if he did he can’t have missed one haunting illustration—executed as a kind of Vitruvian self-portrait—that Taccola included in
On Engines
. The illustration shows a naked figure inscribed in a circle and a square, above which appear a compass, a set square, and a plumb line. On a literal level, these are simply the tools of the architect and engineer. But in the accompanying caption Taccola makes clear that he wants the whole drawing to be understood symbolically, if not in the manner of Vitruvius himself, then at least in the manner of the many medieval illustrators who had summoned up the ghost of Vitruvian Man.
“He from whom nothing is hidden
created me,” the caption reads. “And I have all measure in me, both of what is heavenly above and what is earthly and infernal. And who understands himself understands much” (
Plate 7
).

That’s a potent distillation of medieval ideas about the microcosm. But Taccola provided a twist. Nowhere did he identify his subject as Adam or Christ or God, as Hildegard of Bingen and so many other illustrators had done. Instead, in a shift that reflects the emerging spirit of the Renaissance—and the emerging can-do spirit of the artist-engineer—his subject was the individual, who, through the pursuit of self-knowledge, can access the godlike creative powers latent in all human beings. This was an idea, resonant with Neoplatonic and Albertian overtones, that would appeal greatly to Leonardo when he began to imagine himself as an architect-engineer, and
not long afterward, when he would conjure up his own vision of Vitruvian Man.

L
EONARDO DIDN’T JUST
model his notebooks on the sketchbooks of artists and engineers. He also turned to another source for inspiration: the commonplace book, designed to preserve not pictures but words.

Students receiving a formal education in Leonardo’s day were taught from a very early age to keep commonplace books—notebooks, that is, in which they collected excerpts from their reading, organized not by author or book but by subject. Central to the pedagogy of the age, the commonplace book had two main functions. It helped students develop educationally desirable habits of mind, based on the categories their teachers had them divide their notebooks up into, and it allowed them to organize a store of the best that had been thought and said. This, so the thinking went, would serve them well in their ongoing studies, and, indeed, throughout their lives.

The keeping of commonplace books was so widespread a practice that Leonardo may well have been asked to keep one during the patchy education he received as a young boy in Vinci. If not, he surely came across an abundance of examples in Florence, especially after he began seeking out and spending time with the city’s humanists and scholars. A how-to guide for the keeping of commonplace books even survives from the early 1500s.
“Make a book
of blank leaves of a proper size,” it reads. “Divide it into certain topics—so to say, into nests. In one, jot down the names of subjects of daily converse: the mind, body,
our occupations, games, clothes, divisions of time, dwellings, foods; in another, idioms or
formulae docendi
; in another,
sententiae
; in another, proverbs; in another, difficult passages from authors; in another, matters which seem worthy of note to you or your teacher.”

The instructions were modern, but the practice had ancient roots. Writing in the first century, Seneca had described it in a manner that would have appealed very much to Leonardo.
“We should imitate bees
,” he wrote, using an analogy much cited during the Middle Ages and the Renaissance, “and keep in separate compartments whatever we have collected from our diverse reading, for things conserved separately keep better. Then, diligently applying all the resources of our native talent, we should mingle all the various nectars we have tasted and turn them into a single sweet substance, in such a way that, even if it is apparent where it originated, it appears quite different from what it was in its original state.”

Consciously or not, as Leonardo began to keep his notebooks he combined elements of the sketchbook and the commonplace book. Flitting about very much like a bee in an open field, he observed no real boundaries: he copied the works of artists he admired, he made sketches from nature, he played with ideas for paintings, he drew landscapes and mapped cities, he jotted down his thoughts, he wrote rough drafts of letters, and he began composing formal treatises, almost entirely in his trademark backward script. Farther and farther out he went in all directions, dreaming up inventions both practical and fanciful, experimenting with new kinds of draftsmanship, analyzing geometrical problems, studying the
behavior of light, exploring visual analogies, making lists of things he wanted to know and do, collecting allegories, jokes, and fables.

No matter how disparate his investigations seemed, however, they had a powerful underlying unity of purpose: the search for nectar that he could transform into the sweet substance of his art. The Greeks had been right, he felt. The world was a kind of giant animate being, and even its smallest part contributed vitally to the harmonious functioning of the whole.
“Everything proceeds from everything
,” he wrote, paraphrasing the ancient Greek philosopher Anaxagoras, “everything becomes everything, and everything can be turned into everything else.” Limning the implications of this idea, he anticipated what modern chaos theorists call the butterfly effect.
“The earth is moved
from its position,” he wrote, “by the weight of a tiny bird resting upon it.”

Leonardo covered all of this and much more in his notebooks. What they reveal about his mental life—his preternaturally visual way of thinking, the startlingly free-associative nature of his ideas, the ever-widening range of his interests, the rapidly accelerating pace of his studies and investigations—boggles the ordinary mind. A torrent of ideas and images flooded into his head each day, and he used his notebooks as a way of trying to capture and make sense of them.
“My concern now
,” he wrote at one point, “is to find ‘cases’ and inventions, gathering them as they occur to me; then I shall put them in order, placing those of the same kind together. Therefore, you will not wonder nor will you laugh at me, Reader, if here I make such great jumps from one subject to the other.” Ultimately,
he would fill an estimated thirty thousand manuscript pages with notes and drawings that cover just about every conceivable subject of human inquiry. More than six thousand of those pages survive, some as loose sheets, some in giant miscellanies gathered and bound after his death, and some in notebooks preserved largely as he left them, ranging from large folios to the tiny pocketbooks he kept hanging from his belt. Almost everything we know about Leonardo derives from his notebooks—which, considered together, surely represent the most astonishing testament to the powers of human observation and imagination ever set down on paper.

L
EONARDO MUST HAVE
spent hours every day at work on his notebooks. But he had yet to resolve the vexing practical matter of gainful employment.

By 1483 he had delighted Ludovico Sforza with his music and his verse. Allied with the de Predis brothers, he had even received the commission for the
Virgin of the Rocks
. But he was still far from getting what he wanted: a permanent, salaried position at the court. Not only that, he began to realize that neither music nor painting was likely to allow him to achieve that end. That’s because between 1482 and 1484 Sforza had something more pressing on his mind than art. Venice had invaded Lombardy—and was threatening war with Milan.

Leonardo recognized this as an opportunity. After all, he had learned the techniques of metal casting under Verrocchio and had seen plenty of armorers’ workshops and arsenals in Florence. On his own, he had studied projectile physics and experimented with gunpowder. He had interrogated bombardiers. He
had closely studied the machines and engineering techniques of Brunelleschi, which involved lifting devices and gear systems that could be applied effectively to the problems of siege warfare. He had already constructed at least one stringed instrument, which, as a design challenge, hadn’t differed dramatically from the construction of, say, a crossbow. He had seen illustrations of scores of weapons and machines, both real and imaginary, in treatises on the art of war—most notably in
On Military Matters
by the Italian engineer Roberto Valturio, a volume first published in Latin in 1472 (but then, helpfully for Leonardo, translated into Italian in 1483) (
Figure 24
).

The odds are good that he had also studied the engineering manuscripts of Taccola, who had designed a variety of imaginative, if not always practical, war machines, some of which had been copied by Valturio. By this time he had surely also heard of Francesco di Giorgio Martini—the renowned Sienese artist turned engineer with whom, in 1490, he would travel to Pavia as an architectural consultant for Ludovico Sforza. In the previous decades, Francesco had written his own treatise on military architecture and had won himself a highly respected position in the service of the duke of Urbino.

Military engineering: it seemed a natural choice, representing for Leonardo a chance not only to make a good living and win favor with Ludovico Sforza but also to continue pursuing his endlessly proliferating investigations of how things worked. Since everything was related to everything else, it didn’t really matter where he chose to begin his investigations; no matter where he started, he knew he’d end up arriving at the same universal laws and first causes. War was an unavoidable reality in fifteenth-century Italy and seemed imminent for the Milanese,
so why not make the most of what the situation had to offer him?