home to make his final preparations. He called on a friend and pupil,
young Atalante Migliorotti, to accompany him.
Toward the end of 1482 or the beginning of 1483, with the letter to
Ludovico folded in a leather pouch, Leonardo and Atalante mounted their
horses and left Florence for the long journey to Milan.
5
_Milan_
Milan at this time was one of the greatest and wealthiest city-states in
all Europe. Its battlements and the spires of its mighty cathedral rose
impressively from the lush plain of Lombardy. Towering over the city in
the distance were the snow-capped peaks of the Alps. Groves of mulberry
trees for the production of its famous silk industry and vast stretches
of rice paddies extended far into the surrounding countryside.
Leonardo and Atalante rode along the embankment of one of the many
canals. The sight of the city hastened their pace although the journey
had been a long one. Frequently on the trip Leonardo had stopped to make
notes. Riding over the mountains and ravines surrounding Florence he had
drawn some of the rushing streams and the stratifications of exposed
cliffs. And when they had descended to the plains he observed the
irrigation ditches and made notes on ways of improving the crude systems
of dams and waterwheels.
Leonardo was excited by this new city and by his prospects at the court
of Ludovico. On the way to his lodgings, he also noticed that Milan was
a great center of arms manufacture. Shop after shop displayed its wares
of swords, spears, shields, armor for man and horse, and signs
advertising foundries for the making of cannon. Perhaps here he might
find an outlet for his military inventions.
In the inn where he and Atalante stayed, Leonardo overheard the current
political rumors. All around him was talk of the war. Girolamo Riario
was again in the field, and Ludovico’s ally, Alfonso of Calabria, had
just been defeated by the Venetians in a bloody battle at Campo Morto.
Leonardo reread the letter he had written setting forth his own
accomplishments and decided that now was the time to present himself as
a military engineer. He would minimize the bronze monument, his music,
and his painting, and instead, he would stress his skills in the
inventions of war.
When Leonardo appeared before Ludovico, he was a handsome young man of
thirty-one. Tall and strong, he was dressed not according to fashion,
but simply—almost severely. His hair hung in curls on his shoulders and
his auburn mustache and neatly trimmed beard accented his ruddy
complexion and deep-set blue eyes. Indeed, he presented a striking
contrast to the nobleman seated before him. Il Moro, with his dark skin
and straight black hair, his richly embroidered doublet with its broad
sleeves and the heavy gold chains across his thick chest, was the exact
opposite of Leonardo.
Ludovico set aside Leonardo’s letter, rose from his chair, and walked to
the heavy table on which Leonardo had spread out his drawings.
Plans for all manner of war machines were there—those that Leonardo had
designed for Lorenzo de’ Medici without success, together with many new
additions. For example, there were plans for a self-propelled bomb with
flames to be shot out in all directions—a bomb that was later to be
called a “rotatory rocket” when it was actually invented in 1846.
Leonardo also explained to Ludovico his idea for “poison gas” bombs
containing sulfur: the fumes of these bombs would “produce stupor,” and
they could be used both on land and sea, together with masks to protect
those who were using them. Shrapnel shells, hand grenades, and javelins
that burst into flame when they struck their objectives—these and many
more were among his ideas.
But perhaps the most unusual to Ludovico’s eyes was the design for an
armored vehicle. It was shaped like a giant turtle, with overlapping
sheets of reinforced wood so that enemy shells would bounce off its
surface. The armor was pierced by loopholes for the breech-loading
cannon and there was an opening at the top for ventilation. Power for
the vehicle was supplied by eight men inside turning cranks which in
turn were cogged to other wheels, setting in motion the four drive
wheels. This of course was the forerunner of the tank and the armored
car used in modern warfare.
[Illustration: _Forerunner of the tank or armored car, as conceived
by Leonardo. Motion was supposed to be supplied by four cogged
wheels turned by manpower. Sheets of reinforced wood were supposed
to serve as “armor” against enemy projectiles._]
In addition, Leonardo laid before Ludovico all manner of cannons and
designs for tunneling under the enemy’s defenses. Actually, with respect
to warfare itself, Leonardo called it a most brutal “madness”; however,
he recognized the necessity of being prepared. In his notebook, he
wrote, “When besieged by ambitious tyrants I find a means of offense and
defense in order to preserve the chief gift of nature, which is
liberty.”
Ludovico was very much interested in the things Leonardo had showed him.
Although he was a man of limited imagination and was not able to grasp
the scope of Leonardo’s proposals, he was nevertheless involved in a
war. Since Ludovico’s aging military engineer was to be replaced,
Leonardo left the forbidding castle of the Sforzas with high hopes of
getting the position.
In the meantime, he was commissioned to paint the portrait of a young
girl from a noble family in Milan. At the same time, he began the bronze
equestrian statue of Ludovico’s father, Francesco Sforza. For this work,
he began an intensive study of horses. Since hunting was the popular
sport at the court of the Sforzas, Ludovico owned a stable of the finest
Arabian horses, and here Leonardo commenced his drawings. Again, his
research for a work of art led him beyond just making preparatory
sketches. His studies developed into notes, and his notes into a planned
book on the anatomy of the horse.
During these months of waiting for the appointment as military engineer,
Leonardo furthered his experiments with cannon. In the course of these
experiments, he came across a power that would later revolutionize all
industry—steam. He devised—although he attributed the original idea to
Archimedes—a water vessel connected to a copper tube which was heated by
a fire. The water when flowing into the red-hot tube changed into steam
and the pressure of the steam blew out a ball at the mouth of the tube
with great force. Leonardo experimented with steam in other ways. He
built an apparatus for measuring the transformation of water into vapor.
It consisted of a metal box in which was a thin animal bladder partly
filled with water. Resting on the top of the bladder was a flat lid
attached by a cord hung from two pulleys to a counterweight on the
outside. As the water was heated, the steam in the bladder pushed up the
lid. As the lid rose both the volume and the pressure could be measured.
There were distillation experiments with various condensers, one in
particular that anticipated the modern condenser of Leibig, introducing
double walls that formed a complete jacket for cooling with water in
continual circulation.
Not content with having an idle moment, Leonardo again turned to
searching out books that he had not read and trying to fill the gaps in
his education. He became especially interested in the German
philosopher, Cardinal Cusanus. Cusanus, like himself, had been
influenced by Toscanelli and was a man devoted to the natural sciences.
Leonardo also studied the philosophy of Aristotle and the writings of
St. Augustine. Throughout his life Leonardo believed in an active mind
for, as “iron rusts from disuse, stagnant water loses its purity and in
cold weather becomes frozen, even so does inaction sap the vigor of the
mind.”
Unfortunately, the post of military engineer went to a man named
Ambrogio Ferrari. The extent and variety of Leonardo’s proposals were
too great for Ludovico to trust. He did not believe that one man could
possibly bring all those ideas into being. Ferrari, on the other hand,
was a military engineer only, and a man who was content with the
customary methods of warfare. Furthermore, Ludovico had at last decided
that peaceful negotiations would gain him more than fighting. Thus
Leonardo’s chance of recognition was again postponed.
Meanwhile, the money that Leonardo had brought with him from Florence
was almost gone. He had been forced to move from his apartment to a
single room and now he was barely able to live from day to day. Although
the court of Ludovico Sforza was one of the richest in the world,
artists were frequently treated as servants; often they were the last to
be paid for their services. Also, Leonardo was a foreigner in the city,
which meant he was regarded with suspicion.
Because of these reasons, Leonardo finally decided to do what the
Milanese artists did—they banded together in groups sharing work and
costs. Leonardo had met a young artist of twenty-eight, Giovanni
Ambrogio de Predis, at the court of Ludovico. Ambrogio was court painter
to the Sforza family and had achieved some success. Ambrogio recognized
in the handsome stranger from Florence, however, the touch of genius,
and he realized that his own talents would be furthered by learning from
Leonardo. The two young men decided to pool their abilities. Ambrogio
offered both lodging and a studio; and, in association with his two
half-brothers, one a woodcarver, another a miniaturist, and his elder
brother, a minter of coins, they would not lack for commissions.
Commissions weren’t long in coming. On April 25, 1483, a contract was
signed between Bartolommeo degli Scarlione, a prior of the Fraternity of
the Immaculate Conception, and Ambrogio and Leonardo for an altarpiece.
The fee was two hundred ducats, with a promise of more if it were
delivered on time and was satisfactory to the Fraternity. Delivery date
was to be December 8, 1484. Ambrogio was to paint the altar wings and
Leonardo the center piece—a picture of the Blessed Virgin and Child.
But when the painting was finished, it was not according to the
instructions set forth in the contract. Leonardo had too independent a
mind to be bound by conformity. Nor was it completed on time. Indeed,
for twenty years the quarrel between the Fraternity and the painters
went on. After ten years, Ludovico was asked to intervene for the money
owed; after he failed, another ten years went by and the King of France
himself was finally asked to settle the dispute. Leonardo wanted his one
hundred ducats and the Fraternity offered twenty-five. Eventually, a
secret agreement was arrived at and the painting was restored to
Leonardo and Ambrogio. Leonardo’s painting, the masterpiece entitled the
“Virgin of the Rocks,” now hangs in the museum of the Louvre in Paris.
The day this contract was signed, Leonardo walked back through the city
to Ambrogio’s studio near the Ticino gate. He was low in spirits from
reading the petty instructions of the contract, and, in this mood, he
became aware of the city streets and crowds about him. The noise, the
confusion, the smells—yes, the smells were the worst. Garbage, filth,
and dust were in heaps where the last rainwater had left them and they
buzzed with flies.
Moreover the houses were jammed together and shopkeepers crowded their
wares to the edges of the streets, leaving just enough room for the
occasional horseman to get through. Latrines were only for the better
houses; here, the streets, alleys and even open doorways were toilets.
People flung their scraps out of the window and at night in the poorly
lit streets could be heard the scurrying of rats. Leonardo stopped,
thinking half aloud:
“Two levels. Streets running one above the other—one for pedestrians and
one for carts and horses. Yes, and cutting through the whole city a
system of canals to carry the city’s waste to a river or to the sea. Why
not even ten cities of, say, five thousand houses in each—say, no more
than thirty thousand people to a city?”
Intent now on his thoughts he hurried to his home, his mind busy with
his visions of new cities.
During the years 1484 and 1485 the bubonic plague swept Italy—the same
dreaded Black Death so prevalent in medieval times. Milan was one of the
cities most severely stricken. Every courtyard became a hospital and the
streets were deserted except for the rumbling carts picking up the dead.
On the roads from the city were lines of refugees fleeing to the
country. Surrounding cities that had not been infected manned their
fortress walls as in wartime to keep the fleeing populations out.
Ludovico at first tried to protect Milan from the spread of the disease;
then, frightened, he and his court fled. Even the ruler’s official
documents had to be “disinfected” by perfume and then held for a period
of time before he would allow them near him.
Leonardo, sensing opportunity, drew out his plans for his new cities.
Canals running through them were to be used for barges and the
underground conduits greatly resembled those of modern sewage systems.
Paths were to have gutters for the adequate drainage of the streets.
Public toilets were to be installed. Leonardo even had plans for the
control of smoke collecting over the city—by sending it up tall chimneys
where it was picked up by fans and driven away over the roofs. The
widths of the streets were to be in proportion to the heights of the
houses—light and air would circulate freely. Two levels would be
connected by graceful ramps—the lower level for the commercial traffic
and the upper level for the pedestrians. Where stairs were used they
were designed so one could ascend or descend without one person seeing
the other. Stables were devised so that animals were fed through
openings in their mangers and under these were tunnels of flowing water
for the removal of waste.
[Illustration: _The results of the bubonic plague in Italy, 1484-85.
Streets were deserted except for the carts picking up the dead._]
These sweeping plans Leonardo laid before Ludovico when the epidemic had
subsided. But Ludovico, once his fear was overcome, brushed them aside
as impossible dreams.
So Leonardo returned to the commission for the Fraternity and the
designs for the bronze monument of Francesco Sforza. These jobs kept
Leonardo from brooding about his rejections.
Often, too, Leonardo worked with Bernardino de Predis, the elder brother
of Ambrogio. Bernardino was a minter of coins. As Leonardo watched him
at the laborious task of first cutting disks from ingots and then
hammering the design into the hot metal, he suggested to Bernardino an
easier method, then used in Germany. This was to prepare smooth ribbons
of metal of the desired thickness and with a punch, impress the design
into the ribbon at the necessary intervals and then, punch out the coin.
Leonardo went on to improve this system by designing precise punches for
both faces of the coin. A single machine then cut out and stamped the
coins, using a falling weight raised by little winches. This machine was
later destined for the Vatican mint in Rome.
On March 26, 1485 an event occurred in Milan that was viewed with
mingled fear, superstition, curiosity and excitement. There was a total
eclipse of the sun. To some, coming as it did so soon after the plague,
it was a judgment of God; to others, it was regarded as an omen—a sign
for astrologers to use for predicting the future.
But to Leonardo the eclipse was a moment of great scientific importance.
At this time in history, the Ptolemaic, or geocentric theory of the
universe was the popular belief. This theory taught that the earth is
fixed and the sun and moon revolve around it. Leonardo himself had
believed this theory for a long time. As he grew older, however, he read
and heard discussions of the heliocentric theory. This theory proposed
that the sun is fixed and the earth and stars move around it. Now, as he
watched the eclipse, his doubts of the Ptolemaic concept were renewed
and he resolved to make experiments of his own. The new theory was so
daring for his times, however, that it would be many years before he
became convinced of its truth.
Later that night, deep in thought over the experience of the day, he
noted down his observations of the eclipse and his doubts of the
medieval concept of the heavens. The Church believed the earth was the
fixed center of the universe. Scholars and scientists supported the
belief of Aristotle in the four elements, earth, water, air, and
fire—but something was wrong. What were the planets—what was the moon?
He picked up his pen and on a clean sheet of paper he wrote, “Make
glasses in order to see the moon large.”
6
_The Monument_
During this time, Leonardo had been struggling with the design for the
bronze equestrian statue. Drawing after drawing lay scattered on his
studio floor. Lately, however, a daring plan for this statue had come to
him. It was to be a huge bronze warrior, Francesco Sforza, mounted on a
rearing horse. Weighing perhaps a hundred thousand pounds, it was to be
cast in sections in five furnaces—a fitting monument to the power of the
Sforza family. But there still remained a big problem to be solved: how
could he balance the plunging horse and man on just the two rear legs of
the horse?
Meanwhile, Leonardo had another problem to work on—a wooden model of the
Milan cathedral. He had entered his name with the cathedral authorities
as a competitor in the design and construction of the cathedral’s dome.
Many architects had been brought in and had failed, partly because of
the antagonism of the Milanese workmen to foreign craftsmen, and partly
because the committee found it difficult to decide what designs it
liked. Leonardo had sent them a letter outlining his own recommendations
and had drawn many pages of possible plans. He put forward his knowledge
of various building materials, his understanding of classical
architecture, and his wish to keep his own ideas in harmony with the
Gothic tradition of the cathedral itself. Often he would make a point of
walking about the city, observing the different constructions under way
and drawing up plans to shorten the labor by mechanical means.
In July of 1487 Leonardo received a payment from the cathedral
authorities for the wooden model he had submitted. Still, however, no
final decision had been reached. Now, as Leonardo looked at the model in
his studio, he felt the urge to improve it further—to make it more
perfect. Yet he held his impatience in check and decided he would wait a
little longer. Instead, he decided to work on some of his ideas for
construction devices. He had already made many drawings, but they could
be improved, he thought, and he began to make calculations.
Among these notes and drawings was an improvement on a device for the
raising of columns. It was a mobile windlass with a transmission gear
for transporting and erecting columns and obelisks. Another device was
an earth drill resembling a modern corkscrew with double handle bars.
The upper bar, when turned, drilled the screw into the earth while the
lower bar—when turned the opposite way—carried the dirt up and out. Also
there was a double crane mounted on a circular trolley which carried the
dirt of excavation up and then the crane was moved around on its trolley
so the dirt could be unloaded in different directions.
Other labor-saving devices that Leonardo designed were an automatic pile
driver, the weight of which was raised by a winch and tripped
automatically at its height to fall on the piling; a lift for raising
iron bells to bell towers; and a machine for boring tree trunks to make
pipes for carrying water.
In the fall of 1488, Leonardo was interrupted by a summons from
Ludovico, who wanted him to design and build the decorations for the
forthcoming marriage of his nephew, young Duke Gian Galeazzo Sforza, to
Isabella of Aragon, granddaughter of the King of Naples. He worked on
this steadily until the wedding ceremony in February of the following
year. When the day arrived, the street from the cathedral to the grim
castle was trimmed with flags and banners of the two royal houses. The
inner courtyards of the castle were transformed into delicate arbors of
laurel boughs. Yet it was the evening’s reception and entertainment
which were to be the climax and to them Leonardo had brought all his
mechanical skill. However, the announcement of the death of the bride’s
mother cut short the celebration and, after the bride and groom had left
for Pavia, the wedding party soon dispersed. Disappointed that his
decorations had not been fully appreciated, Leonardo returned to his
studio and the problem of the monument.
He was still struggling with the problem of balancing the rearing horse.
And, indeed, a solution was soon found. By placing a fallen soldier with
his arm upraised in protection under the forefeet of the horse, Leonardo
could balance the enormous weight and provide for the proper casting of
the molten bronze.
Finally, Leonardo made a small wax model of the proposed statue and
showed it to Ludovico. The nobleman was impressed by its originality.
Most of the ideas contributed by other sculptors were mere variations of
what had already been done many times. Also, the other plans called for
bronze of not more than two thousand pounds, while Leonardo envisioned a
statue fifty times that size! Ludovico awarded the commission to
Leonardo.
Leonardo was to work on this commission for ten years and it was
destined never to be immortalized in bronze, for reasons that will be
explained later. His energies, as usual, were poured into many schemes.
Growing out of his work on the monument he planned one book on the
subject of casting in bronze and another on the anatomy of the horse.
But the one subject, which he began to study in this period and which
would occupy the remainder of his life, was the study of human anatomy.
So Leonardo, in the midst of all his other activities, wrote in his
notes, “On the second day of April 1489 the book entitled _Of the Human
Figure_.”
The sources of anatomical study up to Leonardo’s day had been the
Greeks—Hippocrates and Galen—and the Arab—Avicenna. Books on this
subject were few, and the anatomical diagrams were crude and inaccurate.
Galen, for example, had based his studies on the dissection of monkeys.
Renaissance anatomists had explained his errors by pointing out that man
had probably changed since Galen’s time. The Church had stepped in
during the fourteenth century with an edict that was interpreted as a
prohibition against dissection of the human body. In Italy, however,
there were some dissections. They could only use, for this purpose, the
bodies of criminals, slaves, and people of foreign birth. In Florence,
anatomy was studied by the artists, and Leonardo had undoubtedly watched
Pollaiuolo at work on a corpse that that artist had dissected.
In 1489 Leonardo, from the results of his own investigation, produced
drawings of the skull and backbone whose careful attention to detail
are—even today—classics in art and anatomy. With infinite patience and
with a saw of his own invention he had halved a skull and drew for the
first time with accuracy the curves of the frontal and sphenoid bones.
He drew the lachrymal (tear) canal, and he was the first to show the
cavity in the superior maxillary bone—not discovered again until 1651,
by Highmore—now named “the antrum of Highmore.” He was the first to
demonstrate the double curvature of the spine and its accompanying
vertebrae, the inclination of the sacrum, the shape of the rib cage, and
the true position of the pelvis. He planned a whole series of books that
would include from head to foot and from inside to outside every section
of the human apparatus.