Chapter I: Front Matter (1)

_Immortals of Science_

LEONARDO
DA VINCI
_Pathfinder of Science_

_Henry S. Gillette_

PICTURES BY THE AUTHOR

_Franklin Watts, Inc., 575 Lexington Avenue
New York 22, New York_

_To my wife Trudy_

FIRST PRINTING

_Library of Congress Catalog Card Number: 62-8426_
Copyright © 1962 by Franklin Watts, Inc.
_Manufactured in the United States of America_

DESIGNED BY BERNARD KLEIN

AUTHOR’S NOTE

It is natural that, within the confines of these few pages, many facets of Leonardo’s extraordinary personality will be missing. That he was an artist, a man of letters, a poet and a philosopher are well known. That he was also a man of humor, as well as a prophet whose vision extended far beyond his times, are facts that I have also tried to include in this biography. There are many gaps in our knowledge of his life, and these I have sometimes filled with my own imagination to give some continuity to his story. Little is known of his early days, his period of travels after leaving Milan and his years in Rome. There is, too, a certain mystery in his relations to those around him, since our descriptions of him derive mostly from his often cryptic, personal notes and from biographers who wrote of him many years after he had died.

This book is about Leonardo the scientist, and to fully write of his many accomplishments would require an encyclopedic mind. My intent has been to extract the essence of his story in the hopes that it would arouse the enthusiasm of a reader to further his interest in those other, more fully documented books—and, above all, in the notebooks that Leonardo himself wrote.

—H. S. G.

_Rome, August 1961_

_Contents_

1 _The Shield_ 1
2 _Florence_ 9
3 _A Studio of His Own_ 20
4 _Years of Frustration_ 28
5 _Milan_ 37
6 _The Monument_ 49
7 _Success_ 60
8 _The French_ 73
9 _Cesare Borgia_ 86
10 _Shattered Hopes_ 98
11 _The Return to Milan_ 114
12 _Rome_ 129
13 _The Last Years_ 147
14 _Mankind’s Debt to Leonardo_ 159
_Significant Dates in Leonardo’s Life_ 162
_Index_ 164

1
_The Shield_

Dusk was beginning to gather in the valley at the foot of Monte Albano as young Leonardo turned toward home. Stopping by a rushing stream to wash the dust of the day’s explorations from his face, he laid aside his cap and his leather pouch and plunged his hands into the cold mountain water. He felt the force of the current and watched the whirl and flow of bubbles around his bare arms. There was the same feeling, he thought, to the flow of air he had experienced blowing around the rocky crags of the mountains.

This evening, however, there was no time to sit awhile and think. He was in a hurry to get home. Hastily scooping the water in his cupped palms, he splashed it over his head and face, then shaking the water from his hair he rose and picked up his cap. He took a satisfied look in his pouch, slung it over his shoulder and headed down the stony trail to the village of Vinci.

Vinci was a small hill town situated on a spur of Monte Albano. Its castle and the bell tower above the houses seemed like sentinels guarding the slopes of vineyards and olive groves spreading down into the valley.

Leonardo da Vinci, which means “Leonardo from the town of Vinci,” thought about his home. He knew that he had been born in Anchiano, near Vinci, on April 15 of the year 1452, to a peasant girl named Caterina. At the age of five, he had been sent for by his natural father, Piero da Vinci, to come and live at his family’s house in Vinci, a comfortable and roomy place with a spacious garden. Piero, five years before, had married Albiera di Giovanni Amadori, a girl of sixteen. They had had no children of their own, and Leonardo was welcomed into the home with affection by his young stepmother.

When Leonardo was about eleven, young Albiera died, leaving a darkened and saddened house. Two years later his father married another girl by the name of Francesca Lanfredini. Although laughter and song soon replaced the grief, Leonardo never forgot the love of his first stepmother.

Also in the house lived Antonio, his grandfather, who was eighty-five, his grandmother, his uncle Allessandro Amadori and family, and, best of all, his uncle Francesco. The da Vincis, who could trace their beginnings in the town back to the thirteenth century, had always been respected lawyers and landowners. Because Uncle Francesco was neither a lawyer nor a great landowner, the people of the town said he did nothing; but he tended the family vineyards, and, to the delight of Leonardo, he raised his own silkworms.

As Leonardo entered the main gate, he noticed that the oil lamps were being lit above the stalls of the marketplace, and the lively confusion of the last hours of business was in full swing. People nodded and smiled to him, for as a boy of fifteen he was already a striking figure. He was tall with long, auburn hair falling to his shoulders and his face was so charming that it was frequently compared to those of the angels painted in the chapels of the church. The music of his lute, the sound of his voice, and the gentleness of his person were such that all hearts and doors were open to him.

Tonight, however, Leonardo avoided the usual invitations to stop and chat. His father would be back from Florence; he had been going there more and more frequently as his fame as a lawyer grew. Now Leonardo was thinking that he had almost finished the assignment his father, half jokingly, had given him many weeks ago—so many weeks ago that he was sure his father had forgotten about it. At that time a peasant, whose skill in providing fish and game for the table of Piero’s big household was greatly appreciated, had asked a favor of him. This man had a round, wooden shield cut from a fig tree and he had asked Piero to have a design painted on it for him in Florence. Piero, who had noticed the sketches his son was making of plants, rock formations, and scenes in his wanderings about the countryside, decided to test his son’s ability and gave the shield to the boy. In the secrecy of his room, into which no one was allowed, Leonardo had smoothed and prepared the wood, and on it he was painting a monster.

Scrambling over rocks, through streams, and into caves, Leonardo had been in the habit of gathering all manner of creeping and crawling life. Patiently he would bring these home in his leather pouch and carefully study and draw them. Maggots, bats, butterflies, locusts, and snakes added to the confusion of the boy’s already cluttered room. Everywhere he went he collected the things that aroused his curiosity; and as a result, his room was always filled with rocks, dried plants, flowers, the skeletons of small animals—and his pages of notations and drawings. Now Leonardo had combined the features of these small forms of life to make a monster—emerging from a dark grotto and breathing fire and smoke—a thing more terrifying than if done from imagination, for each feature was a duplicate of a reality in nature.

Unobserved, Leonardo reached the privacy of his room and emptied this day’s collection on a table beside the shield. He lit a candle and examined his catch—a lizard and a large grasshopper. These would complete his picture; and, the most extraordinary find of the day—a fossil seashell found high on the slopes of a mountain! How did it get there? Was it a result of the flood about which his religion had taught him? Had an immense wave deposited this ancient sea-life high on the Albano mountains? Looking more closely he saw that it was a type of sea-snail and in almost perfect preservation. This he would have to think about and examine later.

Now, however, the picture must be completed, for he hoped to surprise his father in the morning. But just then, Leonardo heard the family stirring below and his father calling him to dinner. Reluctantly he left his table, made himself presentable and went downstairs.

“Ah, Leonardo,” his father said when he appeared in the family dining room. “I saw Benedetto dell’Abbaco on the way in town and he tells me you haven’t been to school as often as you should—is that true?”

“Yes, Papa—but I’m not doing badly.”

“Signor Benedetto might agree, at least in your mathematics. He tells me you ask him questions that often make him stop and think. But Leonardo, you have other subjects—Latin, reading, and writing—as well as arithmetic. You mustn’t neglect the others, my boy. But come—let us eat.”

Together they sat down with the rest of the family—a large, prosperous, and happy gathering. When dinner was over Leonardo made hurried excuses to all the family, protesting that he was too tired to sing, and escaped back into his room. For a long time he worked, unaware that the house was growing quieter. Finally he laid down his brushes and his maul stick, pushed his chair back and smiled a triumphant smile. The shield was finished. Tomorrow he would ask his father in to look at it.

Conscious now that everybody had gone to bed, Leonardo blew out his candle and opened the shutters. The night sky was a panoply of stars and only here and there was the dark loneliness of the valley relieved by pinpoints of light. Leonardo leaned his head against the window frame and stared at the blue infinity above him. What exactly were the stars? Did all of them move around the earth? What was the haze that obscured the horizon ever so faintly? What was that sea-snail doing in the mountains? Why? How?

The next morning Leonardo found his father and Uncle Francesco in the garden deep in conversation about their vineyards and olive groves.

“Papa, I have a surprise for you up in my room—can you come now?”

“Yes, Leonardo. What is it you have found now—not a better way to raise my grapes, I’ll wager!”

The elder da Vinci put his arm around the boy’s shoulder and went with him up to the door of his room.

“Wait here, Papa, until I say to come in.”

Leonardo unlocked his door, lifted the cloth from the shield standing on the easel and opened the shutter just a trifle so that a soft light filled the room.

“Papa—you can come in now.”

Piero entered—he had long forgotten the round piece of wood—and suddenly he froze in the middle of the room.

“Have mercy on me!” he said when he saw the horrible fire-breathing creature. In the dimness of the room, the monster and the murky cave from which it was emerging were terribly real. Piero actually started to back out of the room in fright, when Leonardo laid a hand on his shoulder.

“Papa, this work has served its purpose; take it away, then, for it has produced the intended effect.”

The shield was the talk of the house; it was set up and marveled at. As for Piero, he resolved to take it with him to Florence secretly and sell it, giving his peasant friend some cheap substitute that he would buy in the marketplace.

So, a few days later, Leonardo’s father saddled his horse and had the shield wrapped and packed in his saddlebag. Also, unknown to his son, he took some of the boy’s drawings. Piero had now realized that Leonardo might have a rare talent. Moreover, he was planning to move to Florence with his family so that he could be nearer to the Badia, or the law offices of the city, for whom he had been frequently employed. There, thought Piero, Leonardo’s talent could be developed under the best of teachers.

It was many days before Leonardo’s father returned; when he did, he gathered his family together and it was obvious to all that he had exciting news. First, Piero announced that he and Francesca would move to Florence since he and a law partner were now engaged in securing office space from the Badia. It was a handsome office centrally located opposite the palace of the _Podestà_, or chief magistrate.

Then, turning to Leonardo, he said: “I have shown some of your drawings to Master Andrea del Verrochio and his enthusiasm for your skill has decided me to place you in his studio as an apprentice. What do you think of that?”

Leonardo was stunned. Verrochio, the great artist and sculptor! Florence! The city-state whose power and influence had spread far beyond her own walls. Now he would study in earnest; now he would find the answers to his never-ending questions. He embraced his father and could say nothing.

2
_Florence_

The Italy of Medieval and Renaissance days was not a unified country as it is today. It was, of course, part of the Holy Roman Empire, but the main governing forces in the land were in the city-states, of which Florence was one of the most powerful. A city-state was much more than a city—it was almost a kingdom in itself. Each had its own army, and very often there were large-scale wars between such city-states as Milan, Naples, Rome, Venice—and of course Florence. The Italians of those days considered themselves citizens—not of Italy as a whole—but of their particular cities; people coming from other cities were looked upon as “foreigners,” even though they looked the same, wore the same style of clothing, and spoke the same language!

All the power, influence, and ideas of this period in history were concentrated within the city-states. A man might be a very fine artist, engineer, or philosopher, but unless he managed to bring his work to the attention of the ruler of one of the cities, he was likely to remain in obscurity. Thus it was that Piero da Vinci, knowing that his son would have to have a powerful patron if he was to succeed at all, brought Leonardo to Florence.

In 1467, when the da Vinci family entered Florence, the city had been under the rule of the Medici family for some thirty-three years. As it was in most of these city-states, the head of the ruling family—at this time Piero de’ Medici—was in charge of the government of Florence and the surrounding countryside. But Piero was fifty-one years old and ailing, and he had only two years of life left at the time of Leonardo’s arrival.

None of this was in Leonardo’s mind as he rode with his father through one of the great, guarded gates of the city. He was thinking, not of politics, but of the fabulous sights that awaited him in this rich center of commerce and activity.

The narrow streets of the city were so crowded that is was necessary for the da Vinci family, together with their servants and the donkeys laden with household effects, to go single file. Leonardo rode behind his father, shouting questions, and, at the same time, turning his head from side to side so as not to miss a thing. Brought up in the solitude of mountains and valleys, and accustomed to the quiet life of a village, the boy of fifteen was overwhelmed with the excitement of the city.

The party was now making its way past the booths of hundreds of shops, past magnificent palaces built by wealthy merchants, and across squares filled with the produce from hundreds of farms. Every now and then, Leonardo caught a glimpse of the cathedral dome, one of the architectural marvels of its day. He had seen the cathedral with its bell tower and also the towering spire of the Palazzo della Signoria—which means the Palace of the Lords—from a hill as they approached the city. This palace still stands and today it is called the Palazzo Vecchio or Old Palace. But now these sights were lost to view in the midst of the narrow streets, other churches, flags, and the lines of washing that seemed to hang everywhere. Frequently, Piero’s party was pressed against a wall as a procession shoved its way through a street. Sometimes it was by armed horsemen escorting a rich banker to some appointment; other times it was a file of cowled monks observing some saint’s day and carrying huge wax candles before them.

After they had crossed the magnificent square of the Signoria, in front of the Palace of the same name, Piero leaned down from his horse and asked a blacksmith where Verrochio’s studio might be. The man shouted above the din of clanging hammers:

“Everybody knows that shop, Signor—it’s down that street and to the right! You can’t miss it—ask anybody!”

The man was right, for the workshop of Verrochio was not hard to find. Verrochio was considered one of Florence’s finest artists and everybody knew of him. He was a short, broad-shouldered man of thirty-two with a round face, shrewd eyes, a thin mouth and dark curly hair that reached almost to his shoulders. In his workshop were two other apprentices—young Pietro Perugino, who was six years older than Leonardo, and Lorenzo di Credi, a boy of eight. They all lived in the house together and, after Leonardo was shown where he would sleep and had put away the few things he had brought with him from Vinci, he was taken to the place where he would work.

Verrochio, whose real name was Andrea di Michele di Francesco de’ Cioni, had taken the name of his teacher, a renowned goldsmith, as was the custom in the shops at that time. Verrochio himself was a skilled goldsmith. But to be an artist and to have your own workshop in the year 1467 meant being a specialist in many things. Into Verrochio’s place came a great variety of artistic work—painting pictures, sculpting and architecture, goldsmithing, designing and making armor, creating decorated furniture, designing mechanical toys, and even preparing stage scenery.

Verrochio, of course, would attend to the greater creative tasks, while his apprentices did the chores of grinding colors, preparing panels for painting, making armatures for his sculpture, hewing to size the marble for a statue, preparing molds for casting, building models for a new palace or church—in fact, all the countless number of preparations to the finished work. Sometimes, if an apprentice showed extraordinary talent, he would be allowed to work on the finished painting or assist with the final strokes of the chisel. Verrochio was a busy man and a successful artisan. To further his own ambitions, he was now absorbed in the perfecting of mathematical perspective and the study of geometry.

The curious Leonardo had come to the right man. In Verrochio’s workshop, where so many crafts were learned at the same time, his powers of observation were able to develop; his hunger to know about mathematics was fed. In Verrochio, Leonardo found a teacher who would encourage these investigations and urge him to study a wide variety of subjects. Leonardo now felt his lack of a fuller education. He started to borrow mathematics textbooks and to seek out men who could teach him what he needed to know. After each day’s work was over, Leonardo would continue on into the night, catching up on his neglected studies and discovering for himself new areas of thought such as anatomy, movement and weight, botany, and another subject which was to occupy much of his later years—_hydraulics_, or the useful application of water power.

In these early years, Leonardo commenced his famous _Notes_. He had developed his own “secret” writing in his childhood at Vinci. These notes—consisting of observations, proportions, and reminders to himself—were inscribed on his drawings. They were, however, unreadable to the eye—until held up to a mirror. Leonardo was lefthanded and could write fluently in this strange manner. It could have been for many reasons that he did so—perhaps from a natural desire for secrecy, perhaps for reasons of safety from possible enemies. In those days, plots and counterplots of all sorts were commonplace—a rumor or a whisper in the right ear could destroy a reputation or financially ruin a career.

Leonardo was popular in Florence. He traveled with the young men of the town, and his handsome appearance and enormous strength (he could bend a horseshoe in his hands) made him a welcome figure in many houses. He continued to play the lute and the lyre. He wrote poetry, composed his own music, and sang with a pleasing voice. His blue eyes were kind and his manner gentle. He always avoided arguments and competition when he could. When he walked through the marketplace and came upon the caged birds, he would buy them—just to set them free. Indeed, his love of animals had become so great that he no longer ate meat.

During these years in Verrochio’s service, Leonardo grew in stature as an artist and rapidly developed into a scientist of promise. He amazed his master when he painted an angel in an altarpiece that had been assigned to Verrochio. He painted it in the new oil colors recently acquired from the Flemish painters. So astounded was Verrochio with its grace that the master vowed he would never lift a brush again if a “mere child” could so surpass him. In this picture there is a tuft of grass beside a kneeling figure, also painted by Leonardo, which indicates by its careful attention to detail the amount of research he did before committing it to canvas. In other paintings he made beautiful drawings of a lily and studies of animals and crabs, giving a hint of what was to come. For, in these preparatory works, Leonardo could not be satisfied until he had thoroughly studied the characteristics of plants and animals in general. Later in life, he was to become more and more absorbed in these researches until they occupied the greater part of his time.

In 1469, when Leonardo had been in Florence only two short years, Piero de’ Medici died and was succeeded by his son, the mighty Lorenzo de’ Medici—or Lorenzo the Magnificent, as he was often called. Now the city of Florence felt itself under the control of a man who really knew how to use power. Lorenzo was Florence; nothing happened without his making it happen, and he became one of the most prominent patrons of art and scholarship in all of Italy. If Leonardo was to make any headway in Florence, he would have to make himself noticed by this new Medici ruler.

But Leonardo was not yet worrying about how to make himself a success. A young man of seventeen and still an apprentice of Verrochio, Leonardo continued to meet new friends with new ideas. It was at about this time that he met Benedetto Aritmetico, a prominent scholar and mathematician. It is probable that this man drew Leonardo’s attention to the practical needs of industry and commerce so that some of Leonardo’s energy was directed toward the study and improvement of existing machinery and the invention of labor-saving devices. At any rate, during these months Leonardo was walking the streets of Florence, wandering into shops and mills, making careful observations of all the various methods of manufacturing. The more he saw, the more he thought to himself that one man could do the work of many—if only he had the proper machine. He even made drawings of laborers with picks and shovels to see if he could determine by mathematics better ways to swing and hold the tools.

In addition, the particular problems in the engagement of joints fascinated Leonardo, leading him on to the study of more general problems such as the transmission of power by gears and the strength of materials. He also spent long hours studying geometrical theories and reading Greek and Latin classical works. Laboriously, he translated these into his own formulas and made comments about them in his notebooks. He attended the lectures of John Argyropoulos, a Greek, who talked of the Aristotelian theories of natural history, and who had translated Aristotle’s _Physics_.

The study of physics opened to Leonardo a whole new world of ideas. He experimented with cogwheels, and with the improvement of ways to lift weights. He became fascinated with the then-known laws of friction and built a bench upon which he tested various devices for the overcoming of frictional drag; he also tested the natural power of one body to set another in motion. This bench with its rollers and weights was similar in principle to the one used by the French physicist A. C. Coulomb almost three centuries later. Leonardo was indeed growing into a man of genius. Now everything from the stars to the flight of an insect occupied his thoughts.

At the same time, he continued his studies of drawing and painting. Frequently he was seen in Florence following someone whose face had interested him—sometimes for the better part of the day—and then at night he would fill a page with sketches of this same person from memory.

By developing his powers of observation in this way Leonardo came to rely more upon his own experiences and less upon what he was told or what he read. This brought him into frequent conflict with the astrologers, the alchemists and even the Church. The astrologers were men who told fortunes by the movements of the stars. The alchemists, with their knowledge of chemistry, pretended to be able to talk with ghosts and to tell the future. These men Leonardo held in contempt. Although he was a devoutly religious man, Leonardo objected to many attitudes of the Church which he considered outmoded and which stood in the way of scientific progress; because of these objections, he was frequently called a pagan.

In this same year of 1469, Leonardo met the aging Paolo del Pozzo Toscanelli. Toscanelli was a famous physician, philosopher and mathematician who, just the previous year, had marked off on the cathedral floor the famous meridian line for determining the dates of the various Church holidays. The old man and the boy became not only the famous teacher and ardent pupil, but close friends.

One evening at Toscanelli’s house, the old man showed young Leonardo a globe of the world. Much of it was marked “unknown,” but Toscanelli had filled in some areas from his own careful calculations and from the stories told him by sailors and travelers. Visions of distant lands, remote mountain ranges and vast oceans filled Leonardo’s imagination as Toscanelli spoke. Then Toscanelli tapped the globe to the westward of Spain, saying:

“Here will be found a quicker route to India than the world has ever known before.” Then, turning to Leonardo he murmured, “You will see it happen, my boy, in your lifetime.”

One by one, Leonardo’s childhood questions were being answered. Toscanelli told him much about the stars, the fossils of creatures long disappeared from the world, and how he believed the earth’s early formation took place. He also taught the boy the art of drawing a map. Not only did Toscanelli greatly influence Leonardo, but the course of history as well. Ten years after Toscanelli had died, Christopher Columbus, struggling westward over the Atlantic Ocean, was using a map that old Toscanelli had sent him, carefully notated with all his accumulated wisdom.

Leonardo, in keeping with his own philosophy, tested all this knowledge with experiments of his own. Because astronomical instruments were rare, crude, and costly, Leonardo borrowed them where he could and later set about making his own. He went on to experiment with time measurements, devising the first example of the application of a pendulum to regulate a clock; by means of two springs, it measured the minutes as well as the hours. So for the next three years Leonardo worked in Verrochio’s studio and continued his studies and experiments.

In 1472 Leonardo’s name was inscribed in the Red Book of the Painters of Florence, which was the official _guild_, or artists’ union of that time. But he was so poor that he couldn’t afford the dues and hardly had the money for the necessary candles to be burnt before St. Luke, the patron saint of all painters. Although his father now had a spacious apartment in a house on one of the main squares of Florence, Leonardo continued to live with Verrochio. In fact, he stayed on past his formal training period for about four more years, grateful to the kindly man for the food and bed he offered.

3
_A Studio of His Own_

On Sunday, April 26, 1478, the bells of the cathedral were ringing loudly over Florence, almost drowning out the noise of the crowds in the street. Shutters were being thrown open and people were shouting excited questions at each other. Distantly at first, but growing in volume, was another sound—an ugly one—the sound of an approaching, angry mob. Leonardo, holding a roll of drawings closer under his arm, stopped and listened.

Suddenly the questioning voices stopped. The bells continued ringing and now the angry shouts of the mob could be heard.

“Lorenzo is dead! Giuliano is dead! Death to traitors! Pazzi! Pazzi!”

“On to the Palace of the Signoria! They’ve captured the Archbishop! He’s a prisoner there!”

“Get a ram and we’ll break the door down!”

The people in the street were caught up in the surging mass. Already soldiers of the Medici were spreading out through the city. Cobblestones were ripped from the street, and swords, knives, and clubs were being brandished in the air.

Leonardo, backed against a wall of a house, was soon left in an almost deserted street. Still holding the drawings, he made his way carefully back to his studio.

As it turned out, Lorenzo was not dead at all.

It was on this Sunday that the Pazzi conspiracy had broken out in Florence. In the cathedral, the ailing Giuliano de’ Medici, brother of Lorenzo, was killed by assassins. Lorenzo himself escaped with only a scratched arm. The Pazzi family were rival bankers of the Medicis and had joined in this plot with Girolamo Riario, a relative of Pope Sixtus IV, and Francesco Salviati, a long-time enemy of Lorenzo. A hired professional thug completed the members of the conspiracy.

Girolamo Riario hated the Medicis because they refused him money for his own ambitions, and the Pope opposed Lorenzo because Lorenzo was supporting raids against papal territory. As for Archbishop Salviati, he had for years nursed a personal hatred for Lorenzo.

When the assassination attempt failed, the Archbishop and Francesco de’ Pazzi fled to the Palace of the Signoria for protection. However, the members of the Council of Florence, who were meeting, then became suspicious and bolted the doors after them. Both men were later killed by the Medici followers and their bodies were hung from the barred windows of the Palace. In the terror of the days afterward, eighty victims lost their lives. The Pazzi conspiracy also had an effect on Leonardo’s future, as we shall see later on.

Leonardo had been on his way to the Palace that morning. He had been given his first painting assignment, or commission, the previous January. This was to paint an altarpiece for the chapel of San Bernardo in the Palace, and just the month before he had received the sum of twenty-five florins as a partial payment.

Some time before January of 1478, Leonardo had left Verrochio and had found a place of his own. The commission had come to Leonardo through the influence of his father, who was now one of the leading notaries, or lawyers, of the city. Though still poor, Leonardo could now devote this new independence to his widening fields of study.

Leonardo’s studio was like his childhood room in one respect—it was still filled with all the different things that had aroused his curiosity. Books were everywhere—on his tables and shelves and piled on the floor—books by Ptolemy, Pliny, and Strabo on geography and natural history, by Aristotle on physics, even one by Guido, a tenth-century monk, who has been called the father of modern music. In addition, there were books on arithmetic, agriculture, geometry, grammar, philosophy, fables, poetry and even one containing jokes. A map of the world hung on the wall, together with his drawings; and, scattered throughout the whole studio were the plants, fossils, rocks and animal skeletons he was still collecting from his trips into the country.

There was also a huge table extending down the middle of Leonardo’s studio upon which were many drawings and instruments for working geometrical problems. His easel near the window supported a painting—a study for his commission in the Palazzo. And on his desk was a confusion of papers containing notes all written in his “secret” writing.

At twenty-six Leonardo was deep in the study of mechanical law, geometry, and botany. For example, he had observed the rings in trees and their relationship to the age of the trees. In mechanics, he was absorbed in drawing models of a “variable speed drive.” By meshing three cogged wheels of different diameters to a common lantern wheel, Leonardo saw that different speeds of rotation could be obtained at the same time. This same principle is used in the gear shift of modern automobiles. About mechanics Leonardo wrote that it was “the paradise of the mathematical sciences because by means of it one comes to the fruit of mathematics.”

Now, too, he was starting to write about his observations on the flight of birds, the formations of clouds and the behavior of smoke in the air. He compared the flying of birds to the swimming of fish in the sea, and the flow of air to the flow of water. Two hundred years before Newton, Leonardo would define the principles of aerodynamic reciprocity, as contained in Newton’s Third Law of Motion.

At this time, Leonardo had an idea for making the Arno river navigable all the way from Florence to Pisa by the addition of canals, thus giving Florence an outlet to the sea. He also had thoughts for the improvement of irrigation in order to make use of land that did not have enough water. Nothing that Leonardo saw in his day’s activities was too small to pass unnoticed and unquestioned. The flight of a butterfly, the stratification of rock in a cliffside, the shape of a mighty cumulus cloud, the turning of a carriage wheel on a bumpy road, the play of muscles in a farmer’s back, the curling of water around a rock in a stream—all of these aroused Leonardo’s curiosity. Continually, he studied these things and painstakingly drew them and wrote about them in his notebooks.

Unfortunately, Leonardo’s painting commission for the Palace of the Signoria was never completed. By the end of the year 1478, the Pope, angered by the killing of the Archbishop during the Pazzi conspiracy, had declared war on the Republic of Florence. Ferdinand, the King of Naples, was persuaded to help in this war against Florence and the Medicis. As the papal forces were approaching the fortresses on the Florentine hills, the Council of Florence discontinued Leonardo’s commission in order to conserve money for the defense of the city.

Disappointed though he was, Leonardo did not allow this setback to discourage him. From a page of drawings in the Uffizi Gallery of Florence on which are sketched various arms and war materials, we learn that he turned from his artistic to his mechanical skills and began designing engines of war. Besides being a Florentine concerned with the defense of his city, Leonardo was eager to gain an appointment with Lorenzo as military engineer to make up for the painting commission he had just lost. Also, as the fifteenth century was a turning point in the methods of waging war, Leonardo was attracted to all the mechanical possibilities of the new artillery. Before then soldiers had used spears, bows and arrows, and stone-throwing catapults, among other primitive methods. One of Leonardo’s designs included a light cannon whose barrel could be raised or lowered to proper elevation by means of a hand-cranked screw and whose horizontal direction could be determined by a maneuverable cradle.

The military appointment that Leonardo hoped for didn’t come. Unfortunately for the Medicis, the war with the papal forces was being lost. One by one, the fortresses under siege surrendered; more and more of the Florentine troops were fleeing.

Leonardo continued the work on his military machines for, although he was having some success painting Madonnas for private homes and had even received a commission from the King of Portugal for a tapestry design, he still wanted official recognition for his inventions from Lorenzo de’ Medici.

During these weeks late in the year of 1479, Leonardo conceived many ingenious devices to wage war. Besides the small artillery piece, he designed a _bombard_, or rock-throwing cannon, which did not recoil when it was fired. This was followed by a light gun arranged in three tiers of barrels, mounted so that while one tier was fired, the second was being loaded and the third was cooling (a forerunner of the modern machine gun). Another was a device to repel enemy ladders. It consisted of a horizontal beam laid parallel to the top of a fortress wall; the beam could be pushed outward by one man or several men using a system of pulleys.

Unfortunately for Leonardo, just as he was ready to show these inventions to Lorenzo de’ Medici, the last fortress outside Florence surrendered and a three-month truce followed. Lorenzo himself went to Naples and persuaded King Ferdinand to withdraw from the war. By 1480, peace returned once again to Florence.

As for the Medicis, military machines no longer interested them. Greatly disappointed at not having his inventions used—or even looked at—Leonardo began to search about for new fields of creative activity.

4
_Years Of Frustration_

The old monk spread the papers out before him on the table.

“Master Leonardo,” he said, “these are the terms of the commission. We at the monastery wish to have an altarpiece painted for our chapel. Your father has recommended you, and, as you know, he is our lawyer. Of course your reputation has already reached our ears, and we are satisfied in our choice.”

The year was 1480. The monk represented the monastery of San Donato a Scopeto near the Porta Romana, just outside Florence. Leonardo shook his head slowly at the terms of the commission. The painting had to be completed in thirty months at the most. Moreover, he must pay for his own colors and even—Leonardo looked up as if to protest but resumed reading—even pay for any gold or gold leaf he might use. Nevertheless, it was an opportunity, and Leonardo needed work. Since the papal war had ended, he had not received any commissions—and his skill at military engineering was still too unknown to have won him recognition.

Although Lorenzo de’ Medici was a great supporter of the arts and sciences, he had not granted Leonardo any of his patronage. In Lorenzo’s court were many men with much book-learning but little talent. They guarded their positions jealously and kept the way to Lorenzo barred to any applicant whom they did not like. Of them, Leonardo wrote in his notes: “They strut about puffed up and pompous, decked out and adorned, not with their own labors, but by those of others, and they will not even allow me my own. And if they despise me who am an inventor, how much more blame be given to themselves, who are not inventors but trumpeters and reciters of the work of others?”

In accepting the commission to paint the altarpiece, Leonardo hoped to attract attention to himself. Perhaps then Lorenzo might welcome him to his court and grant him patronage. So, with his usual thoroughness, Leonardo set about the task of preparing an Adoration of the Magi—a favorite subject of that time. This was to be a picture of the Holy Family surrounded by the three wise men from the East, shepherds and animals, old and young, rich and poor, paying their adoration to the Christ child.

Since he wanted his subjects perfect in every detail, Leonardo set about drawing countless youths, old men, sheep, oxen, horses, and donkeys. In a separate drawing for the background, he worked out with mathematical mastery the problems of perspective, that is, drawing objects to make them appear three-dimensional and either close or far away in space. In addition, he made studies for the composition of the whole picture—studies in which his knowledge of geometry was used to heighten the excitement of this great religious subject.

Among these sketches that Leonardo made for his “Adoration of the Magi” is a page on which appears an inspiration for one of his greatest masterpieces—a drawing of the “Last Supper.” And on this same page is another drawing—one of a hygrometer. A hygrometer is an instrument for measuring the amount of moisture in the air. Leonardo’s design consists of a simple, graded disk with a balanced pointer, weighted at one end with sand and at the other with a sponge or some salt. As the sponge or salt absorbed the moisture in the air, the added weight was indicated on the graded disk, thus measuring the amount of humidity.

Leonardo’s researches for the altar painting took him almost a year. Although the monks began to grumble at his slowness, Leonardo would not be hurried. He was determined to produce a painting that was perfect in all respects. To quiet their impatience Leonardo did odd jobs for them in the cloister. He repainted their old clock and for this extra work they advanced him some much-needed money. In March of 1481 Leonardo was ready to begin the actual drawing for the altarpiece. As he progressed with the composition, the monks crowded around with exclamations of delight. So different was it from all the other Adoration pictures they had ever seen, that the monks sent Leonardo some sacks of corn as a token of their appreciation.

One day, Leonardo was walking slowly toward the monastery over the Ponte Vecchio—the Old Bridge—across the Arno River. He made his way slowly up the hill past the construction for the new Pitti Palace. The morning was hot and the farmers moving into the city with their heavily laden carts were short-tempered. Leonardo stood to one side as he watched a pair of oxen straining to haul a wagon up a rise in the road. Their owner, his shirt unbuttoned to the waist, was shouting angrily, lashing the animals with his leather-thonged whip. It was a cruel sight and Leonardo turned away. From some experiments he had been making, Leonardo realized that the poor animals were struggling not only with the hill, but the drag of friction on the creaking axle. This drag could be eased, he thought to himself, by simply resting the axle in two sets of roller-bearings attached to the bottom of the cart near each wheel. In his mind he formed the plan for such a model as he made his way to the monastery.

The drawing of the altarpiece was nearing completion. The monks were fascinated by the spectacle of the Adoration appearing before their eyes. The soft, umber outlines deepened with gray, the ochre highlighting the central figures charmed them and they sent another gift to Leonardo’s house—a cask of Tuscan red wine.

As it turned out, Leonardo never finished this altarpiece. It is not known why. But the drawing for it can be seen today in the Uffizi Gallery in Florence just as Leonardo left it.

It is certain, however, that Leonardo was far from idle during this time. He drew the design for eliminating the friction of a turning axle by mounting the axle in roller-bearings. He experimented with, and solved the problem of, transmitting motion to revolving machine parts by friction—the possible forerunner of our modern friction clutch. Another device, found in modern automobiles—the differential—was also drawn by Leonardo. This idea provided for the difference in speed between the two drive wheels when rounding a curve.

Leonardo also drew the first known plans for a self-propelled vehicle—an “automobile.” It was designed to operate by a system of elastic springs wound by hand by the person on the vehicle; the “car” was then supposed to run the short distance allowed it by the unwinding of the springs.

In addition, Leonardo continued designing machines for both offensive and defensive military action. One of these was a breech-loading cannon, together with the first known projectiles that took into consideration better penetration through the air and greater stability in their trajectory. Indeed, these very much resembled present-day aerial bombs, with pointed noses and stabilizing fins.

As the months passed, however, Leonardo began to feel that his time and talents were being wasted in Florence. Although the monks and friends of the monastery were pleased with the work he was doing, other artists were being called to greater tasks in Rome. For example, Domenico di Tommaso del Ghirlandaio, Sandro Botticelli, and even Leonardo’s fellow student, Pietro Perugino, had left Florence to work in the chapel of Pope Sixtus IV in Rome—known to us as the Sistine Chapel. Now, too, it was becoming clear that Lorenzo and his court had no time for this solitary genius whose ideas stretched beyond his age.

So Leonardo looked about him. He was thirty years old and the walls of Florence seemed to bind his spirit. To what city could he go where his talents would be put to fruitful use? Rome seemed to hold out no hope, for no one had offered him a position there.

But Leonardo remembered that there had been a visitor to the Medicis from another city in recent months. This man was Ludovico Sforza, the ruling prince of Milan, the great city-state of the north. Ludovico, who was also called “Il Moro” (the Moor) because of his dark complexion, was seeking the friendship and alliance of the Medicis. He was fascinated with the art and culture of Florence and sought to gather to his own court of Milan as many artists, scientists, philosophers, and musicians as he could.

Perhaps, thought Leonardo, his future lay in Milan. So he began collecting his countless drawings, diagrams of machines and instruments of war, his notes, his plans for canals and irrigation—even a drawing for a monument that he knew Ludovico wanted to erect to his father—and made a package of it to send to Ludovico. Then he sat down to write a letter to that nobleman. In it he set forth in ten numbered paragraphs his qualifications as military and naval engineer, architect, and hydraulics expert. Almost as an afterthought to the tenth item, he wrote: “I can carry out sculpture in marble, bronze, or clay, and also I can do in painting whatever may be done, as well as any other, be he who he may.”

When he had finished the letter, Leonardo took out a strange instrument. It was a lyre of silver in the shape of a horse’s head. He had designed it himself, and now with an air of peace, he commenced to play. Its rich tone was sweet to hear and the music was his own composition.

Leonardo had also designed other instruments—lyres, lutes, viols, and a kind of zither. He had perfected the single-stringed monochord of Pythagoras, replacing the tablet of wood with thin strips of drum that gave the instrument a low or high note according to the tightness of the string. In addition, he introduced stops or small pistons in the holes of wooden reed instruments; and, he had even invented a set of mechanical chords by using a wheel of reeds which plucked a set of strings as it was turned. His skill as a musician, composer, and singer was well known among his friends and his bass voice had retained the pureness of his boyhood.

As it happened, news of Leonardo’s silver lyre had reached Lorenzo de’ Medici. All Leonardo’s paintings, all his designs for cannons and fortifications, all his inventions for commercial machinery had failed to interest Lorenzo—yet this single musical oddity excited the ruler’s curiosity. Leonardo was summoned to the Medici palace.

Lorenzo was enchanted both by the instrument and Leonardo’s musical talent. When Leonardo had finished playing, Lorenzo, surrounded by members of his court, applauded and said,

“It would please us if Master Leonardo da Vinci would present us with this beautiful instrument so that we, in turn, could make a gift of it to His Highness, Ludovico Sforza, of Milan.”

Leonardo bowed and replied,

“Your Grace’s request is my pleasure. Moreover, Sire, it would further that pleasure to bear the gift myself to His Excellency in Milan.”

The idea delighted Lorenzo. He immediately directed that Leonardo be given a letter to Ludovico and that every protection be given Leonardo for his journey.

Leonardo, with the silver lyre and the letter of recommendation, hurried 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.