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.

As his notes began to take shape and he thought of printing them, it was natural for the inventive Leonardo to design his own printing press. It is one of the earliest such designs on record. Because the carrying bed which held the type and the paper was automatically adjusted to the handlebar, the press could be operated by one man. Besides his notes Leonardo also considered printing a work by Roger Bacon, the thirteenth century English scientist.

This project for printing his own books, however, was never realized by Leonardo. Lately, he had received a commission which took him back in memory to the days of Ludovico. The subject was Marshal Gian Giacomo Trivulzio, a soldier-of-fortune. Originally this man was a loyal commander of Galeazzo Sforza’s but when Ludovico came to power he had had Trivulzio banished from Milan. Embittered, Trivulzio had become a stubborn enemy of Ludovico from that time on, serving under any banner that marched against the house of Sforza. A stocky, square-faced man, his body was covered with the scars of many battles. He had been fighting with the French ever since the time Ludovico had betrayed Charles VIII. Trivulzio had seen the great monument that Leonardo had modeled and, although it was riddled by French arrows and damaged by wind and rain, the Marshal was impressed and wished for a similar memorial to himself.

Leonardo set to work immediately. His past experience with the Sforza monument was now to his advantage. This time there was no need for experimenting. He knew how much material he needed and the approximate cost of everything including the casting. He submitted an estimate of three thousand and forty—six ducats for the completed work, one hundred of which would go to Leonardo. The sum was acceptable to Trivulzio and Leonardo began his preliminary studies.

As he gathered the material for this new equestrian statue, Leonardo and the French Viceroy Charles d’Amboise became interested in the further canalization of the plains of Lombardy. The use of canals and locks had been in practice for roughly a hundred years and around Milan there were already some fifty miles of canals and about twenty-five locks. Leonardo started another survey of the area. In his imagination, he envisioned a vast hydraulic engineering project.

On September 12, 1508 Leonardo announced in his notes the beginning of a book on the nature of water. He had decided to separate this book from the one on hydraulics because it was necessary to separate theory and practice. His pages treating the science of hydraulics, or the practical applications of water power, had reached to “forty books of benefits.” By the spring of 1509 he had expanded his notes on the nature of water to include the greatest wave to the smallest raindrop.

Concerning the practical applications of water power, Leonardo put forth many designs for new locks. He introduced new methods of raising the gates by windlasses and chains which could easily be set in motion by one man. But most important is Leonardo’s discovery of the use of centrifugal force for draining marshes—the ancestor of the centrifugal pump. When you rapidly rotate a stick in a pail of water, the water spins in a spiral rising on the sides, and, if you rotate the stick fast enough it bares the bottom of the pail. When you remove the stick suddenly, the water continues to whirl as it slowly subsides.

This is basically the same principle Leonardo used to raise the water from a marsh to a level above the sea so that it could be drained away.

The centrifugal pump was also used with a hydraulic screw which converted water power to mechanical power. The force of a stream of water was injected into the base of a vertical cylinder. In the base of this cylinder was a six-bladed propeller mounted on a vertical shaft. The force of the water turned the screw and at the same time the water was forced to rise in the cylinder to an outlet above. The turning propeller revolved the vertical shaft. This shaft, emerging from the top of the cylinder, turned a cogged wheel. This wheel was joined to another cogged wheel mounted on a horizontal shaft, thus providing the mechanical power. Not only is this the forerunner of the turbine, but the use of the propeller, itself, for propulsion in water, was a new idea not to be thought of again until the eighteenth century. For certain types of hydraulic pumps he conceived of the cone-headed mitre valve still in use today.

Leonardo, besides studying the practical applications of water power, explored the very nature of water itself. In his proposed books on this subject he intended to examine why clouds and fog form, why rain falls and the raindrop itself—even how the raindrop is held together. He understood the nature of capillary attraction, which holds the raindrop together, and his notes show us that he was exploring the science of hydrostatics which relates to the pressure and equilibrium of liquids in general.

Now that Leonardo had a steady income and the relief from meeting painting commissions by fixed dates, he was free to explore his other favorite avenues of knowledge. It seemed that his ever-active mind could never stop roaming over the whole field of scientific knowledge. He continued with his early interests—the nature and movement of air, astronomy and geometry. He was also still concerned with movement and weight, for he set down in his notes, “The thing which moves will be so much the more difficult to stop as it is of greater weight.” This is a hint at a principle formulated by Isaac Newton almost two hundred years later in his First Law of Motion—the law concerning inertia. For example, the motion of an arrow shot into the air maintains itself in flight so long as the influence of the initial force is maintained in it.

On a note dated April 28, 1509 he wrote, “Having for a long time sought to square the angle of two curved sides ... I have solved the proposition at ten o’clock on the evening of Sunday.” As always, Leonardo was deeply involved in the study of mathematics. Too deep perhaps to recognize the new rumblings of war.

Louis XII, still pursuing his campaign in northern Italy, had again arrived in Milan amid the salutes of the French artillery. Following his personal banner of a gold porcupine on a white field, he had come back prepared to do battle with the Venetians whose power, as it diminished in the east, was extending westward into Italy. Alarmed at this Venetian expansion, the French King had allied himself with Pope Julius II and the powers of Europe to form the League of Cambrai to push back this threat. Charles d’Amboise, the French Viceroy, had already taken to the field and at the castle of Cassano, overlooking the Adda river near Milan, he awaited the arrival of his king.

By the end of May, Leonardo was in the saddle once more. Surrounded by the best knights of France and the nobles of Milan, he personally accompanied the French King as military engineer to the meeting with the Viceroy of Milan at Cassano.

During the next three months, through the battles and defeat of the Venetians at Aquadello where sixteen thousand dead were left on the field, and the siege of Caravaggio and the capture of Peschiera, Leonardo served as military consultant and map maker. More than ever his eye was attracted to the possibilities of utilizing the many rivers they crossed both for warfare and commerce. He envisioned making the Adda river navigable from Milan to Lake Como. During this time, he devised not only a revolving bridge but even one of two layers in a single span—the upper level for pedestrians and the lower one for vehicles.

By July, Leonardo had returned with the king and the French army to Milan. Here was planned a great celebration of the French victory over the Venetians. In front of the cathedral, to the delight of the hundreds of spectators, Leonardo devised a mechanical lion scaring a dragon out of an artificial lake into the beak of a cock which picked the dragon’s eyes out. After the festivities Leonardo returned to his everyday work. In time, he had a thriving workshop and as he became more and more preoccupied with his scientific explorations, his art commissions were turned over to his assistants. He did continue, however, to work on the plans for Marshal Trivulzio’s monument and in his preparatory work for this assignment he expanded his notes and drawings of comparative anatomy.

This renewed interest in anatomy led him to attend a lecture in the winter of 1509. The lecturer was Marcantonio della Torre, a young man in his late twenties and one of the best-known anatomists of the times. He had been a professor at the University of Padua, but this city had fallen into the hands of the Venetians. Marcantonio was forced to flee Padua and had settled at Pavia. The two men, when they met, recognized in each other a devotion to science and they began a professional collaboration that grew into a friendship. Leonardo now developed his anatomy studies to the point where he is today recognized as the foremost medical anatomist of the Renaissance.

Returning to his dissections, Leonardo now proceeded to explore the heart and system of veins in the human body. His drawings of the heart are nearly perfect. Indeed, he was probably the first to discover the endocardium membrane that sheathes the valves and sinews of the heart. Also, he pictured and described the moderator band, “the first cause of the motion of the heart.” His work on this organ led him to the doorstep of discovering the circulation of the blood—later to be carried out by William Harvey in the seventeenth century.

Further, Leonardo was the first to accurately draw a representation of the foetus, or unborn child, in the womb of its mother, writing in his notes that, “we conclude therefore, that a single soul governs the bodies and nourishes the two.” In addition, he drew a remarkable picture of the female figure and for the first time accurately placed her organic structure. In his notes, he also pointed the way to the laws governing metabolism when he wrote, “The body of anything whatsoever that receives nourishment continually dies and is continually renewed....” By pouring wax into a hole in the skull he made the first casts of the ventricles of the brain. Several hundred years were to pass before this method was rediscovered.

As Leonardo’s work progressed, his admiration for the complexity of the human body grew. Many times in the middle of explaining a section of anatomy he inserted a sentence or two of wonder or praise at the magnificent creation that is the human being. Indeed, these drawings and notes represent the sum of many, many dissections; moreover, Leonardo had to work under conditions that placed many obstacles in his path—the crude lights and instruments, the difficulties of obtaining corpses and, above all, the opposition of the superstitious and ignorant.

The following year Leonardo entered in his notes, “This winter of the year 1510 I look to finish all this anatomy.” And yet, however sincerely he might express such a wish, Leonardo was a person who was literally never “finished.” The scientific and artistic tasks he had chosen for himself were clearly beyond the limits of any one man. Besides, the pressures of the outside world were once more threatening the peace and quiet of his home and work.

Pope Julius II became increasingly fearful of the French victories over the Venetians. Secretly, he concluded a peace with Venice and, allying himself with his former enemy, he now turned against the French. When the conflict continued, Charles d’Amboise, the patron of Leonardo, was killed at the battle of Correggio. He was replaced by a new French Viceroy, Gaston de Foix. Although the Pope now hired Swiss mercenaries, this invasion from the North was defeated by the young Gaston. Not to be outdone, the Pope then brought in Spanish troops.

In the ensuing bloody battle at Ravenna, the French completely defeated the armies of the Pope and Spain, despite their use of battle-cars armed with razor-sharp sickles on their wheels—strangely like the early inventions that Leonardo designed for Lorenzo de’ Medici! Although the French were victorious, they lost their brilliant young leader, Gaston de Foix, and with him they lost their heart. As a result, they were soon disorganized. The Pope’s armies renewed their attacks, and the French began a long retreat.

Once again the plague infested Milan and Leonardo’s friend, Marcantonio della Torre, died of it. After some futile attempts at recovery, the French fled across the Alps and with them went Marshal Trivulzio. Milan was left temporarily under the martial rule of the Swiss, and Leonardo with only his few apprentices was left again without a patron.

Tired and prematurely old at sixty-one, Leonardo resignedly gathered his possessions together once more and with Francesco de’ Melzi and four of his loyal pupils, he turned his back on Milan for the last time. The date was September 29, 1513. Their destination was Rome.

12
Rome

“Name?”

“Leonardo da Vinci.”

“Where from and where are you staying?”

“We are coming from Milan by way of Florence. I have quarters being prepared for me at the Belvedere in the Vatican—by order of the Pope. Now, young man, let us pass.”

The guard at the Porta del Popolo changed his manner. He dropped his halberd and motioned to the other guards to let the riders through. He touched his helmet roughly and with a grin he said,

“I’m sorry, Sire—but you know how it is. All these people—there’s bound to be them that we don’t want here. Go ahead, your Excellency. Make way there!”

With these words he laid his spear against a jostling group of broad-hatted pilgrims blocking the entrance to the city of Rome.

Leonardo heeled his horse and with Francesco de’ Melzi at his side, followed by his servant and students, pushed past the crowd at the gate. To the left rose the Pincio hill with its stately pines where, in the days of Imperial Rome, Lucullus had walked in his gardens. But Leonardo had no time to look about. It was a damp December day, and rain threatened from the gray skies. He was tired, and as Francesco glanced at him he could see Leonardo pull his cape around him with a little shiver as the chill wind stirred the long, graying hair on his shoulders. They made their way through the crowded, noisy city. They crossed the Tiber and rode past Castel’ Sant’ Angelo, the papal fortress built on the tomb of Emperor Hadrian. After another inspection by the Swiss guards in beribboned uniforms of white, green and gold under their shining breastplates, they entered the walls of the Vatican. That evening after he had settled himself in the Belvedere apartments and dinner had been eaten, Leonardo, gazing into the embers of the fire, looked back over his new stroke of fortune.

The Medicis had returned to power. Pope Julius II had died, and Giovanni de’ Medici, son of Lorenzo, had become Pope Leo X at the age of thirty-seven. With his election to the head of the Christian world, the Republic of Florence became a city of the Medicis once more and Leonardo had received an appointment in Rome. Giuliano de’ Medici, Pope Leo’s favorite younger brother, in his new rise to power and wealth, became Leonardo’s patron. The two must have met sometime during the Medici’s exile. Leonardo was given the apartments in the Vatican and a salary of thirty-three ducats (approximately eighty-five dollars) a month and a workshop was fitted for him and his pupils. He was also assigned an exclusive German assistant named Georg.

The Pope’s court in the Vatican was like the Medici court in the Florence of Leonardo’s youth—multiplied by hundreds. Leo X saw himself as the center of the artistic world, and being a man of luxurious tastes with the wealth of the church behind him, the Vatican was soon filled with a mixture of the wise and foolish. Pompous classic-quoters, third-rate poets and clowns mixed with the world’s scholars and statesmen. The two greatest artists were Bramante, the architect and friend of Leonardo’s first years in Milan, and Bramante’s pupil Raphael, the painter.

Bramante was busy building the new church of St. Peter’s and, as the architect of this favorite project of the Popes, he was sole master of the Roman art world. Raphael, as his protege, was the recipient of the better painting commissions in Rome. The elderly Bramante and the thirty-year-old assistant were a famous pair in the Rome of 1513. Equally as famous, however, was Michelangelo; he was still living in Rome, but was without patronage after Julius II’s death. Leonardo’s old rival had scored his triumph with his extraordinary paintings in the Sistine Chapel.

Although the young Raphael, who owed so much to the example of Leonardo, now rode through the streets as a wealthy nobleman, Leonardo himself received no great commissions. While Pope Leo was indulgent of his brother’s whims he himself had no use for this tall, serious old man who roamed the shaded walks of the Vatican poking at the strange plants in the botanical garden or making drawings of the foreign animals in the private zoo. In reality, Leonardo’s patron, Giuliano de’ Medici was a weak man. He played at being a patron but, like his brother the Pope, he lacked the force and decision of his famous father Lorenzo. Nevertheless, he did give Leonardo one small commission for a picture. Immediately Leonardo, excited by the exotic plants in the Vatican gardens, commenced to experiment with them to find a resin to make a varnish with which to cover the future painting. Pope Leo made fun of him exclaiming, to the delight of his court, “This man will never get anything done, he thinks of the end before the beginning.”

This ridicule by the Pope made Leonardo a joke to many in the circles of the Vatican who were a little afraid of this strange man with the searching eyes. Leonardo also suffered the humiliations of a man who did not conform to the fashions of his day. His knowledge of Latin, for example, was weak and although he could read it with the help of a dictionary he could not speak it. And, among the people who surrounded the Pope, Latin was the only language allowed. Prizes of great sums of money and important positions were often granted on the strength of an improvised speech in Latin (with many quotations from the classical authors) or a flattering Latin verse. Faced with such setbacks and ridicule, Leonardo—not surprisingly—began to withdraw into himself.

And yet, Leonardo refused to remain idle—he had to work. The need for mirrors in the vast halls and rooms of the papal palace was great. Leonardo turned his mechanical skill to redesigning and improving methods of making them, and even inventing his own machines for the grinding of the glass. Also, for Giuliano, who dabbled in alchemy and magic, he made distorting mirrors and burning lenses. In addition, Leonardo invented a machine which could be run hydraulically for producing long strips of copper of equal width for use in soldering the mirrors.

But, with the making of these mirrors, Leonardo began to run into trouble with his German assistant, Georg. The boy was a loafer; he spoke little Italian and took every opportunity to spend his days with his countrymen in the Swiss guard. Leonardo tried to alter the situation by suggesting that the boy have his meals with him at his worktable, thus giving Georg a better chance to learn the language. This however did not appeal to him. Then, because Leonardo’s inventions were so extraordinary, he began to give away the secrets of their mechanisms to Johannes the mirror-maker, another German, who had been replaced by Leonardo in the favors of Giuliano. This naturally made Johannes jealous of Leonardo. Georg gossiped, too, and told stories about the old, eccentric man who lived like a miser in the midst of all the luxury and who drew crazy circles on pages of paper.

These “crazy circles” were geometric exercises that had fascinated Leonardo from the time he had wandered across Italy with Fra Luca Pacioli. Pacioli’s book De Divina Proportione, containing sixty illustrations from designs of Leonardo, had been published in Venice in 1509. Leonardo intended to entitle these geometric exercises De Ludo Geometrico. In geometry a lune is a crescent-shaped figure bounded by two intersecting arcs of circles on a plane or a sphere. Leonardo drew pages of these lunes and then proceeded to transform their curvilinear figures into squares of equal area. He also reviewed Archimedes’ method of squaring a circle and developed it into a variety of ways for cubing spheres and cylinders.

He returned as well to formulating theories of friction. He wrote in his notes, “the tallest wheel is the easiest to pull”—for example, a big wheel turning at the same speed as a smaller one has less friction to overcome because it makes less revolutions. His experiments in friction predated men like Amontons and Coulomb by two and three centuries. He established a formula for the building arch which he described as “a strength caused by two weaknesses”—if one half of an arch is removed, the other half collapses. They support and give strength to each other. In addition, Leonardo determined, before Galileo, the center of gravity of any pyramid and of a tetrahedral, or four-sided body.

As the days went by and he waited for commissions to come, Leonardo took to wandering about the streets of Rome. He stood in the half-buried Forum of the Caesars surrounded by grazing sheep and grunting pigs. Wooden shacks where crude cartwheels were made and where the marble from the ancient temples was cut and sold, were built against the sides of crumbling ruins. The old triumphal arches, now overgrown with creepers, were boarded into towers and cattle were penned between the shafts of columns that once supported the grandeur of temple roofs. Here and there a classical scholar would be sketching or writing from the worn, Latin inscriptions on a marble slab tilted crazily from the ground where it had fallen hundreds of years ago. Goats wandered on the Palatine hill, once the home of Emperors, and the great baths of the Emperor Diocletian were now a deer park and a hunting ground for royalty.

During the course of these wanderings, Leonardo became interested in the primitive methods of carpentry. Such things as screws, for example, were rare. Those that were used were either made of wood or, if of metal, by goldsmiths laboriously making each one by hand, soldering wire around a pin and another wire into the hole to hold the screw. Sometimes they were made by filing pieces of metal individually. All these methods were time-consuming and costly.

Leonardo had thought of this problem before, and now he concentrated on perfecting his ideas about it. Previously, he had thought of casting the metal in wooden molds and then turning the metal on thread-cutters. The designs he finally drew in careful detail, however, are essentially the methods used today. The new machines did with a few turns of a handle and adjustments of a few cogged wheels what it took one man many hours to perform. He also drew designs for a mechanical plane and a machine for drawing wire that worked by water power.

Leonardo now lived and worked in the Belvedere of the Vatican—more a man on exhibition than an active participant in the great artistic activities taking place around him. True, he received his thirty-three ducats a month, but Michelangelo had been paid three thousand for his work in the Sistine Chapel, while Raphael had earned twelve thousand for each room he painted in the Vatican.

Thus Leonardo drifted farther and farther away from his painting. This, in itself, caused people to talk in the papal city. For he had earned fame as a painter, but his passion for science was regarded as strange and whimsical. Occasionally, he did receive a small commission from the workshop of Raphael, yet these were like the crumbs from a rich man’s table.

Even the toys Leonardo made at this period for the amusement of his patrons were looked upon as somewhat weird. For example, he would take small pieces of wax and mold them into strange little animals and then inflate them so that they floated in the air in front of a startled guest. Once he caught a curious lizard in the garden and spent hours putting scales all over the tiny body, attached to it a little beard and horns, then let it out from a box at a banquet. The guests jumped back with fear and the women became hysterical.

One of Leonardo’s jokes that has been passed down in accounts of his life at this period must have created quite a sensation. He showed the company the cleaned entrails of a sheep resting on the palm of his hand. After telling them to wait and watch he took the entrails in another room and with a bellows inflated them with warm air. As the entrails filled with air they expanded and extended. They crept into the room where the company waited. Slowly they grew and grew until they began to fill the room. The guests overturned their chairs in their hurry to get out of the way of this shapeless, translucent creature. Then Leonardo appeared, the air-filled entrails giving way before him, and said:

“Sires, this is but an example and symbol of virtue. As you can see, the smallest virtue is capable of the greatest growth.”

The guests laughed, but it was an uncomfortable laugh. Thus another story was added to the legend of Leonardo as an odd old man.

Leonardo, whose work—particularly his anatomical studies—had constantly been interrupted by the fortunes of war, had found another hospital in Rome where he could continue these studies. This time it was his intention to write a treatise on speech. He dissected and drew the anatomy of the larynx (the voice box), the vocal cords and the trachea (the air passage to the lungs), and all the muscles that control the movements of the tongue and the lips. If you pronounce each letter of the alphabet you will feel these muscles of the lips, especially with the letters “o,” “p,” and “f.” Carefully he noted how the air vibrations from the trachea form themselves into vowels and consonants, and he drew the membrane which, when air is pressed against it, makes the sound “aah.”

At this same time he was also busy finishing a treatise on painting which he had begun when he was working on the “Last Supper” for Ludovico Sforza. But it was for his knowledge of military engineering that he was sent to the city of Parma by the Pope on September 25, 1514. Here he stayed at the Bell Inn while examining the fortifications and other defenses of the city.

Leonardo’s patron, Giuliano de’ Medici, had been appointed governor of this particular area and, since Pope Leo X was fearful of two powerful countries, France and Spain, he was preparing the papal territory against possible invasion. Another fear of the Pope—and indeed of everybody in Rome—was malaria, the disease carried by the mosquitoes that bred in the Pontine marshes west and southwest of the city. At that time, however, no one knew the cause was mosquitoes; rather, they thought it was the bad air from the marshes.

As Leonardo had already been effective in draining the pestilential marshes of Piombino for Cesare Borgia and, later, those around Milan for Charles d’Amboise, he was assigned the same task for the Pontine marshes. He surveyed the entire area to the sea and made another extraordinary aerial type map. His recommendations included draining the entire area, enlarging and regulating the Martino river and cutting an extra outlet from the river Livoli to the sea. These plans were adopted some years later and parts of the marshes were drained successfully, yielding new land for the cultivation of crops.

By December of 1514 Leonardo had finished his treatise on speech and, possibly in an effort to attract the attention of the Pope, he submitted it to the Privy-Chamberlain, Battista dell’Aquila. As Pope Leo was surrounded by an army of secretaries and assistants who passed on everything submitted, this manuscript with its beautiful drawings was mislaid and lost and only a few notes and sketches remain.

The continual discouragement of his life in Rome was offset by a visit from his half-brother, Giuliano, around Christmas. Leonardo was held in esteem by his family despite the quarrel over his father’s and his uncle Francesco’s will, and his half-brothers were pleased to tell of their famous relative who lived in the Belvedere as guest of the Medicis. Yet they knew little of Leonardo’s scientific dreams and his lack of recognition in the papal city.

Often, Leonardo’s greatest comfort was to return to his notes. The challenge of geometry and the mysteries of the movement of air and water kept him from brooding about his lonely life. Francesco de’ Melzi, Leonardo’s young friend, had more and more taken over the practical responsibilities of his everyday life. Except for his workshop, where the troublesome Georg worked at the making of mirrors, and an occasional small commission for a painting, Leonardo was free to study.

In addition to his geometrical investigations, Leonardo now experimented with the science of statics (objects that are stationary), and dynamics (objects in motion). One of his most important discoveries in the science of mechanics came about during this period. Concerning the division of weight, he wrote, “There are three conditions of gravity of which the one is its simple natural gravity, the second is its accidental gravity, the third the friction produced by it. But the natural weight is in itself unchangeable, the accidental which is joined to it is of infinite force, and the friction varies according to the places wherein it occurs, namely rough or smooth places.” Thus he realized and formulated what composes the movement of an object. He found that movement is the result of separate forces acting upon the object from different directions, as for example, the initial push, the pull of gravity and the resistance of friction. And, before Galileo, Leonardo further experimented with objects dropped from a height. As the result of repeated experiments, he noted that the fall was being affected by the earth’s rotation. That is, the object dropped always fell in a slight eastward direction rather than vertically downward—a fact later proved conclusively by Isaac Newton and Robert Hooke in the next century.

He also became fascinated with spiral motion, such as is found in a spinning top or in a whirlpool of water. Because of his interest in hydrodynamics, or the movement of water, he began to sketch imaginary “Deluge compositions.” These were drawings showing the world—probably inspired by the Bible—in a chaos of wind and floods. They were based on his years of scientific research. Indeed, his drawings of actual whirlpools are still among the greatest of his scientific art. Today, with all the latest technical aids, such as dusting a whirlpool with powdered rosin and then photographing it, an accurate three-dimensional picture is impossible. Yet Leonardo, by sheer observation and analysis coupled with his genius for drawing, could reproduce the complicated shape of whirling water.

In the relatedness of his explorations of water, air and movement, and weight, he worked out the similarity between the laws of equilibrium controlling solids and liquids. The equation between the motive force and resistance that makes for equilibrium or balance in solids can be compared to the equation between the upward pressure of liquids and the downward pressure exerted on them.