Leonardo da Vinci, Pathfinder of Science

Part 7

Chapter 74,078 wordsPublic domain

Leonardo now plunged into a winter of great activity. Forced to draw from his savings, he had rejoined the guild of painters in October of 1503, and then applied for the commission of painting the murals in the council chamber of the Palace of the Signoria. It had been planned to decorate this great hall with scenes commemorating famous Florentine victories, and Leonardo chose the battle of Anghiari where the soldiers of Florence defeated the Milanese in 1440. In addition to working on the “Mona Lisa” and continuing with the canal project—for which he was now designing great suction pumps to lift rivers from one level to another—he turned again to astronomy and geology.

Leonardo, while investigating the course of the upper Arno, had come across much evidence that the land there had at one time been completely under water. Various types of ancient ocean life and vegetation lay scattered in layers along the ridges of the mountains, and these Leonardo collected and brought back to his studio. He wrote, “above the plains of Italy where now birds fly in flocks, fishes were wont to wander in large shoals.” He reread Ptolemy, the ancient Greek geographer Strabo, and even Sir John Mandeville, an English author of travel books, in his quest for knowledge of distant places. He talked to travelers, sailors, and wrote to friends to send him information about the countries they had seen or lived in. Strabo, in particular, had set forth the doctrine that the earth’s transformation had taken place by the forces of volcanoes and water, but the wisdom of these early men had been obscured by the closed minds of the Middle Ages.

Even in his own time of reawakening knowledge—the Renaissance—Leonardo had to contend with the combined superstition of the Church and the ignorance of misguided scholars. For example, the Church believed in the great flood, as described in the Bible, and the scholars claimed that if what Leonardo said were true—that the earth was the result of an evolutionary process—there would have been written records. To this latter Leonardo responded, “... sufficient for us is the testimony of things produced in the salt waters and now found again in the high mountains far from the seas.” But Leonardo’s conception of the evolution of the earth was mistaken in one respect. He regarded the earth as organic—living—and the flow of water he believed to be like the flow of blood in man. Indeed, according to Leonardo, all living creatures were reflections of a living, breathing earth. It was only when he again turned his eyes inquiringly toward the moon and the laws of the universe that he began to realize his error.

It had been the idea that the earth was the center of the universe which supported Leonardo’s theory of an organic earth. Yet after years of observation and study he abandoned this theory and, with the eye of a man centuries ahead of his time, he wrote in his notes, “The moon has every month a winter and a summer. And it has greater colds and greater heats and its equinoxes are colder than ours.” He went further and identified the elements existing on the moon such as “water, air, and fire,” and described them and their functions as being like those on our own earth. In so doing he recognized the existence of the moon as a solid in space, reflecting the light of the sun—one of many “stars” in a universe. With his acceptance of this concept he realized that the earth could not be organic.

In May of 1504, the Signoria complained to Leonardo that there had been no progress on the proposed paintings for their council chamber, even though he had already been partially paid for them. Accordingly, he was forced to sign a document that he must be finished by February of next year or refund all monies paid him. As was his custom he had made many preliminary drawings. Although he was well acquainted with horses he had again researched their anatomy and actions. Pages of rearing, frightened horses and men in combat covered his studio tables. On one of these pages there are sketches of the heads of a lion, some horses and a man—all with fierce expressions on their faces. Here Leonardo hinted at the comparative anatomy of expression in man and animal that Darwin was to write about almost four hundred years later.

But the paintings could wait, for now the Arno River was in spring flood. The time had arrived to make the first attempts at diverting the river into its new course. Leonardo was again in the field supervising the work. There had been much opposition to Leonardo’s canal from both the army captains and the Signoria. It was called a whim and a crazy idea, but Piero Soderini and Niccolò Machiavelli were stubborn in their defense of Leonardo’s plan and they overcame all opposition to it. And indeed, the raising of the sluice gates was successful and the Arno actually flowed into its new bed. The tensions in the camp and in the Council of Florence were eased. The only sad person was Leonardo, for he had just learned of the death of his father.

Leonardo felt the loss deeply. Outwardly, however, he only acknowledged the death of his father at a distance. Not only had Leonardo and his father drifted apart over the years, Piero left nothing to Leonardo in his will. His father’s other children quarreled among themselves over what money he did leave. Leonardo’s one friend in the family was Uncle Francesco, who was still living in Vinci. When he heard of his brother’s will, Francesco made out a will of his own and left everything to the nephew he loved—Leonardo.

After having successfully diverted the Arno river, it was now necessary for Leonardo to return to the painting commissioned by the Signoria for its council chamber. But recently, Leonardo had suffered a rebuff in this work. Originally he had been given the whole room to do but now the opposite wall had been assigned to another man—Michelangelo Buonarroti. Leonardo had first met the young Michelangelo when he helped to judge the best location for Michelangelo’s monumental statue of David. The two men were opposites in every way. Leonardo, fifty-two years old, carefully dressed, cool and detached, was a man whose every action was the result of a thoughtful and analytical mind. Michelangelo, twenty-six years old, his clothes rumpled and covered with marble dust, was passionate and moody—an impulsive youth totally dedicated to art. They did not like each other, and now Leonardo was forced into a rivalry for which he had no heart.

The duel between these two giants of art aroused the whole of Florence and there was a constant stream of people watching them at work. Michelangelo was given a studio in the hospital of Sant’ Onofrio and Leonardo was working in the Papal Chamber in Santa Maria Novella. Among the many people who came to watch Leonardo was a young man of nineteen. He was already a pupil of Perugino and the experience of meeting and learning from Leonardo was to influence him the rest of his life. His name was Raffaello Sanzio—one of the great Renaissance painters of Italy and known to us by the name of Raphael.

While Leonardo worked at Santa Maria Novella he had the opportunity of continuing his studies in anatomy. Dissections at that time were novelties and when one was performed the doors were thrown open to the public. Leonardo must have attended the public dissections at the Church of Santa Croce. Now at Santa Maria Novella there was a hospital, and here Leonardo was able to continue his own dissections without interruption. In a cool room below the hospital where bodies were kept Leonardo worked late into the night. By the flickering lights of candles and in the silence of the world about him he studied, drew, and wrote in his notes of the wonders of the human body.

He performed autopsies on people who had died natural deaths—a special permission granted to him by the monks of the church, and among these autopsies are the first written reports of some of the diseases that are the causes of death. Arteriosclerosis, or stony growths in the blood vessels, and pulmonary tuberculosis, a nut-like growth in the lung, are among the discoveries Leonardo made in his lonely searches, although he did not use these medical names for them.

Above all Leonardo was attracted to the function of the muscles, especially those in the arms and legs. So faithfully, in fact, did he record the origin and insertion of all the various muscles that these drawings can be used as anatomical models today. Moreover, he believed that a good drawing was worth pages of words describing human anatomy. The muscles were rendered as cords so as to better understand their function. He described this function as one of pulling instead of pushing and he noted that for every muscle there is an opposing muscle. When one contracts the other expands. For example, when you tighten the biceps in your arm you can feel the looseness of the triceps, the muscle on the opposite side.

As the end of the summer of 1504 approached, Leonardo’s dream of the canal from Florence to the sea was destroyed. The summer had been hot and without rain. The water in the canal dried up and the Arno river returned to its original course. All the old arguments against the plan were revived. The Florentine army captains rebelled against the job of defending a useless project. Again Soderini and Machiavelli intervened. After heated debates in the Council of Eighty, which had been called into special session, Machiavelli himself was sent out to oversee the work. It was brought almost to completion when in late October disaster struck. The rains that had failed to come in summer fell from the heavens in great cloudbursts. Storm after storm swept the valleys. The workmen left and the soldiers were recalled. The Pisan army rushed in to fill up the diggings and one final storm washed away the dream to nothing but eroded mounds of dirt.

Leonardo buried his disappointment in other work. When the drawing for the Battle of Anghiari was ready for transfer to the wall of the council chamber, he had a special scaffolding made of his own invention which worked on the principle of a pair of scissors standing on end, with a long platform on top. As the legs were spread the scaffolding was lowered and when they were pinched together it was raised. The wall had been prepared with a special mixture which he hoped would bring out the brilliance of his tempera colors. With several assistants who had been assigned to him by the Signoria the violence of the Battle of Anghiari was transferred to the wall and the actual painting was begun.

During the winter months Leonardo would relax from his work on the huge painting and his dissections to roam the country around Florence. He visited the slaughterhouses where the animals were killed and prepared for market. Here he was able to examine the hearts of animals just slaughtered and to note that the heart retained its action until the body was almost cold. He made a glass model of the aorta (the main artery leading from the heart) of an ox with which he could experiment on the flow of the blood. He intended to add to it a glass tube for one of the semilunar valves of the heart. He also experimented with a frog, dissecting its brain, heart, and entrails and noted that it ceased to twitch only when the spinal cord was severed. In his notes, he wrote, “The frog instantly dies when the spinal cord is pierced; and previous to this it lived without head, without heart or any bowels or intestines or skin; and here therefore it would seem lies the foundation of movement and life.” He was of course searching for the reasons that muscles moved and from where the impulses originated.

One of Leonardo’s favorite places to visit was Fiesole where his uncle Allessandro Amadori lived. Uncle Allessandro was the brother of Leonardo’s first stepmother and, since he had loved her so much, he likewise felt an affection for Allessandro. At Fiesole, which rises over Florence in a steep ascent, Leonardo could watch the birds circling in the air below him.

On these lofty heights, he would unfold his drawings of flying machines. Leonardo had progressed now to a point where an actual flight was all that was left. He had designed a sort of flying boat—a shell with wings that moved up and down and he had introduced a tail like that of a bird. He had noted that the tail of a bird acts as a rudder, a stabilizer and a brake when landing.

But Leonardo’s most recent design was one that was called an _ornithopter_. It consisted of a wooden frame, two huge wings like a bat’s, a series of ropes and pulleys and a windlass, all planned with the lightest of materials. The flyer, lying prone in the frame, his feet in leather stirrups connected to the wings by pulleys, would move his feet up and down to flap the wings while, at the same time, he operated the windlass with his arms in order to guide the machine. Soon he hoped to build this machine and try it out.

Meanwhile, Leonardo returned to his painting in the council chamber with impatience, for spring was approaching and the time to finally realize his dream of flying would be at hand. Aside from an assistant who had tested the pedals and windlass, no one knew of his plan to actually put his machine in the air.

Weeks passed and the painting was almost finished. The huge wall was covered with plunging horses and embattled soldiers. The colors were brilliant on the special mixture he had prepared for the wall—but they were not drying as they should have. Something was wrong. To speed the drying process, Leonardo had a special fire built in the room that directed the heat onto the painting. Spectators were allowed to watch as the waves of hot air rose against the wall. Then—disaster began slowly with a small trickle of paint from the top! Before anybody could put out the fire, the great figures and horses slowly melted down the wall in shiny, sticky streaks of color. Leonardo fled the room in an agony of shame.

With his own friends discouraged, the Signoria hostile, and the friends of Michelangelo triumphant, Leonardo went back to Fiesole. He went back with his secret dream of flight. The world would soon forget the Battle of Anghiari—but the conquest of the air, if he could achieve it, would live forever.

In the spring of 1506, from the slopes of Monte Cecero near Fiesole, legend tells us that a great bird sailed into the air and disappeared. No one knows whether Leonardo actually flew his machine or not but Girolamo Cardano, the son of a friend of Leonardo, wrote, long after Leonardo had died, “Leonardo da Vinci also attempted to fly, but he failed. He was a fine painter.” Another dream had been shattered.

11 _The Return to Milan_

Leonardo felt his fifty-four years that spring day in 1506. The bitterness of his failures and the frustration of his dreams added considerably to the weight of his years. All morning he had wasted in argument with Soderini and the Signoria. If it had not been for the letter from Charles d’Amboise, Viceroy of the King of France for Milan, he would have felt like a beggar. Charles d’Amboise had been appointed military governor of Milan by Louis XII ever since the French had conquered that city and captured Duke Ludovico Sforza. But the authority of the letter had finally won a grudging consent from Soderini. Leonardo looked about him to see if he had forgotten anything and slowly climbed onto his horse. He nodded to Salai, his apprentice, looked back to see if his servant had the pack-horses ready, and started down the street leading the small procession. He was going back to Milan.

Leonardo took out the letter and reread it. The words were respectful and admiring—and in French. They requested the presence of “Maître Leonard de Vinci” at the court of Charles d’Amboise, for purposes of painting and other “diverse projects” for the King of France. The letter restored a measure of confidence to Leonardo’s self-respect. Before Leonardo left, Soderini had made him sign a letter in which Leonardo promised to return to Florence within three months and to leave a deposit of one hundred and fifty florins which would be held against his return. It was signed, notarized and dated May 30, 1506. Nevertheless, Leonardo had decided to accept the French envoy’s offer; moreover, he looked forward to the prospect of returning to his vineyard at Porta Vercellina and the understanding of a sympathetic patron.

Indeed, Charles d’Amboise turned out to be more than sympathetic. He recognized Leonardo as a great artist; but even more, he was one of the few patrons who could appreciate the magnitude of Leonardo’s scientific and mechanical genius. In the court of Charles, Leonardo once more enjoyed a time of peace and an assured income. The French Vice-Chancellor of Milan, Geffroy Carles, who was second in command, was also a distinguished scholar and a patron of the arts and natural sciences. With the admiration and support of these two men and especially with the distant backing of King Louis XII of France, Leonardo’s dismal memories of Florence began to fade.

Leonardo’s three months’ allotted absence from Florence, however, were soon past and a letter arrived from Soderini demanding either Leonardo’s return or a forfeiture of the one hundred and fifty florins deposit. Now a tug-of-war developed between the Viceroy of Milan and the governor of Florence over Leonardo. The Signoria reminded Charles that Leonardo had his work to complete, while Charles d’Amboise and Geffroy Carles demanded an extension of time. One month more was granted. More letters were exchanged until the affair became so heated that the King of France himself intervened. In January of 1507 the French King informed Soderini and the Signoria that Leonardo was “not to move from Milan until our arrival.” Since Florence at this time was under the protection of the French, such final authority silenced the Signoria. Shortly afterwards Leonardo discharged his obligation to the Signoria by relinquishing the one hundred and fifty florins, and he at last became free from the demands of his native city.

On May 24, 1507 King Louis XII re-entered Milan with all the splendor and color that France and the Dukedom of Milan could confer upon their ruler. Knights in armor and the ladies of the courts followed the king who rode in flowing white and gold under a canopy of blue decorated with the lilies of France.

With such pomp and display in Milan, Leonardo was soon back at his old occupation of designing pageants and tournaments. While some of the people from the days of the Sforzas returned, not many remembered Duke Ludovico, who was slowly dying in a French dungeon. Among the people that Leonardo now met, there appeared Francesco de’ Melzi, a noble from an old Milanese family, who entered Leonardo’s life at this time as a pupil. Soon the young man became like a son to Leonardo. Of handsome appearance, he had the sensitivity to appreciate the essential loneliness of Leonardo and so, almost without realizing it, he filled a gap in Leonardo’s life that was to last until the end of his days.

Yet, as Franceso de’ Melzi opened one door of Leonardo’s life another door closed. He received word that his beloved uncle Francesco had died at Vinci and that he had become the heir to his uncle’s property. No sooner had this news been delivered when Leonardo was notified that Giuliano, a son of Piero, and now a lawyer in his own right, was contesting the will. All the frustrations of his life in Florence now rose to an angry pitch and he set out once again for Florence to fight for his own rights.

Wisely, Leonardo had armed himself with letters from his new, influential patrons and even one from King Louis himself recommending, “... we request that you will cause this dispute to be settled in the best and briefest delivery of justice....” In August of that same year—1507—Charles d’Amboise added his personal letter suggesting that the king could not spare Leonardo too long from the court at Milan.

It was with the title of Painter and Engineer to the King of France that Leonardo rode back to Florence to await the outcome of the judges in his case. He went to stay with a sculptor friend, Giovanni Rustici, a man of thirty-five and also an ex-student of Verrochio. They lived in a house lent to Rustici by a wealthy scholar and patron named Piero Martelli.

Leonardo soon found that he and Rustici had much in common. Rustici, too, collected the odds and ends of his journeys into the country. Flying about the house were a tame eagle and a raven, while, at dinner, a pet porcupine begged for food. Rustici, however, was a believer in alchemy and magic. To practice these arts the young man devoted one room to the strange mixtures which bubbled over flames as he attempted to change base metals into gold, or to call upon the spirits to predict the future.

Leonardo settled into the life of the house very quickly and even helped his friend on an important sculpture commission. This was a group composition of St. John between the Pharisee and the Levite for over the doors of the baptistry. He also started to gather together his scattered notes on all the subjects that he had written about, going through them making corrections and erasing the repetitions. Possibly Leonardo was considering the publication of all his material for he wrote, “Begun at Florence in the house of Piero di Braccio Martelli, on the 22nd day of March, 1508. This will be a collection without order, made up of many sheets which I have copied here, hoping afterwards to arrange them in order in their proper places according to the subjects of which they treat....” This “collection without order” of almost forty years extended into practically all branches of human knowledge, founded on years of observation and experiment. Indeed, it was the magnificent effort of one extraordinary mind to push back the curtains of ignorance in order to let the light of natural truth shine through to mankind.

In addition, Leonardo returned to his studies of anatomy and comparative anatomy. For this latter he made many beautiful drawings of the legs of animals as compared to those of man. With them, Leonardo tried to indicate man’s place in the natural order of the world. He pointed out that our physical bodies are basically the same as those of animals, and that the muscular and organic differences are those of function only. For example, bird and man have the same chest muscles, called the pectoralis. But the bird, in order to fly, has developed these into powerful instruments of motion. Man, on the other hand, has learned to stand and move in an upright position. He has developed the muscles of the back, called the erectores spinae, and those of the buttocks to hold him erect. Leonardo intended to enlarge upon his studies of comparative anatomy to include all living creatures, even the insects.

Meanwhile, the Viceroy of Milan was becoming impatient for Leonardo’s return. The judgment against his half-brothers had been settled in Leonardo’s favor, and he hastened back to Milan. By the summer of 1508 he was once more in the routine of the court’s activities. King Louis had granted Leonardo a regular allowance and it was the first time he had enjoyed such a long freedom from the concerns of earning a living. With these steady payments Leonardo now had the leisure and support to pursue his own multitude of interests.