Initially trained as an artist, Leonardo also compiled notebooks filled with thousands of pages of his drawings and descriptions of a number of scientific, mechanical, and technical subjects.
The notebooks of Leonardo da Vinci, never published during his lifetime, filled some thirteen thousand pages. Leonardo had bequeathed the work to his constant companion, artist Francesco Melzi, who, in turn, bequeathed them to his son, Orazio. As Orazio had no interest in the notebooks, he gave many away. The Literary Works of Leonardo da Vinci
An estimated seven thousand pages are known to exist, dispersed throughout France, Italy, Spain, England, and in private collections. In 1994, Microsoft Corporation founder and chairman, Bill Gates, bought the most famous collection, the Codex Hammer, restored to its traditional name, the Codex Leicester
Leonardo da Vinci was born on April 15, 1452, the illegitimate son of Piero da Vinci, a notary, and a peasant woman known only as Caterina. Because the Italian middle classes of the fifteenth century ostracized those born out of wedlock, Leonardo could not attend a university or enter a profession such as medicine or law. He demonstrated talent in music and art as a child, so his father in 1465 or 1466 apprenticed him to the famed Florentine artist Andrea del Verrocchio. Upon concluding his artistic apprenticeship in 1478, Leonardo embarked on a lifelong program of self-education. While many classical authors were accessible in Italian translations, Leonardo lacked knowledge of Latin, the language of most scientific works. He taught himself the language in the late 1480’, and though he never fully mastered it, he used it to report his discoveries.
During his early days in Verrocchio’s workshop, Leonardo developed an interest in engineering and practical mechanical problems. He became an independent artist in 1478, the approximate date of the first folios of the scientific and mechanical studies collected into the various notebooks.
During his lifetime, Leonardo enjoyed the reputation of both engineer and artist. The earliest notebooks reflected two main interests: military technology and the study of acoustics and design of musical instruments. His early sketches include improvements on musical instruments and their odd combinations. No model or finished instrument exists, however.
Having gained familiarity with bronzecasting in Verrocchio’s studio, Leonardo drew up elaborate technical plans to cast a huge horse for a monument for his patron, Ludovico Sforza in Milan. The early notebooks contain sketches of cannons, an armored tanklike vehicle, automated and labor-saving devices such as a military drum with six automatically controlled sticks, machines to pump water to lay siege to towers, and an underwater breathing apparatus.
During his association with Sforza (between 1483 and 1499), he sketched a parachute, pumps, irrigation systems, and digging machinery. Later, he drew various flying machines, among which was a helicopter-like contraption. Numerous drawings of gears also exist, reflecting his response to one of the greatest problems of contemporary technology: friction and the loss of efficiency due to inadequate construction. He devised clever equipment, including friction banks, conducted experiments, and derived several still-valid principles of friction. His interest in economy and practical efficiency led him to conceive devices that would reduce friction, including worm gears and ball bearings.
The notebooks that were written during the 1490’s also reveal the development of a holistic view of nature; Leonardo’s study of optics is an example. As an artist, he was interested in vision and light and in shadows and colors, and as a scholar, he was familiar with classical and medieval theories of light and vision, including the traditional explanation that the eye gave off light. He joined an interest in water behavior with light to propose a wave theory of light, analogous to the propagation of transverse waves generated by dropping pebbles in water. He proposed that sound was a wave phenomenon and speculated that waves could also explain smell.
In his earliest anatomical investigations, Leonardo dissected the eye and may have been the first to understand the function of its lens. In turn, he related the eye to the camera obscura and then drew a sketch of a projector.
Whereas a few anatomical drawings date from his earlier notebooks, Leonardo probably had few opportunities to do actual dissections until perhaps the first decade of the sixteenth century. By mid-decade, he claimed to have dissected ten human bodies, and in 1507 he performed a postmortem on a man who had claimed to be one hundred years old. His drawings of humans sometimes included animal parts, such as the cow cotyledons depicted on the human uterus. His drawing of the fetus is quite accurate, as is his osteology (descriptions of bones) and myology (studies of muscles).
Leonardo approached anatomy from the viewpoint of engineering; the bones were levers and the attached muscles represented the lines of forces acting on them. He analyzed complex motions such as supination and pronation and correctly illustrated them.
Leonardo made some admirable contributions to anatomical method. For example, he devised an ingenious method to study the brain: He filled the ventricles of the brain with wax to preserve their shape. Moreover, he introduced to anatomy the techniques of representing structures from different aspects and of displaying cross-sections. At first, Leonardo accepted Aristotle’s physiology, then Galen’, and, at the end of his life, moved beyond the ancient views. Leonardo also did comparative anatomy.
Manuscripts on mechanics reveal that Leonardo had absorbed medieval works on levers. He worked with the bent-lever law and extended it. His mechanical writings included considerations of tensions of weighted cord segments; the problem of the center of gravity of systems of bodies in equilibrium, such as suspended beams with attached weights; and the problem of the determination of the center of gravity of solids. Other topics included hydrostatics and theories of violent and inertial motion based on the medieval concept of impetus. His ideas on motion informed his conception of life, which he defined as a form of motion. He also studied percussion, which along with movement, weight, and force comprised the four powers of nature.
Botany, perspective, physiognomy, and the science of water also received Leonardo’s attention. In the science of water, Leonardo was involved in a plan to divert the Arno River to facilitate communication between Pisa and Florence.
As Leonardo did not publish any material from his scientific, mechanical, and technical notebooks, he cannot be said to have exerted a major influence on the development of science. To his credit, however, his notebooks are representative of what could be known during his time. The extensive discussions of technology and the drawings representing his inventions (few of which were ever built) indicate the state of technology during his lifetime and illustrate its theoretical problems and problems of applicability.
Moreover, he represented the growing awareness of the importance of mathematics in understanding the physical world, recalling astronomer Galileo Galilei’s much-later dictum—“the book of nature is written in mathematics.” Leonardo’s ideas still reflected classical and medieval learning, however, as, for example, in his acceptance of the microcosm-macrocosm analogy. His practice of performing experiments and dissections anticipated the methods employed more systematically in the later successful investigations of Galileo and of the anatomist Andreas Vesalius.
Leonardo’s goals reflected the nature of a Renaissance figure who wanted to understand natural causes and effects and to use that knowledge to control nature. In the end, his science is a complicated blend of inherited knowledge, imaginative speculation, intense inquiry and discussion, observation, and experimentation.
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Ahl, Diane Cole, ed. Leonardo da Vinci’s Sforza Monument Horse: The Art and the Engineering. Bethlehem: Lehigh University Press and Associated University Presses, 1995. An account of the reciprocal influence of Leonardo’s artistic and technical interests as illustrated by plans for a huge equestrian monument, the model of which was greatly admired though never cast. -
Farago, Claire, ed. Leonardo’s Science and Technology: Essential Readings for the Non-Scientist. New York: Garland, 1999. A collection of previously published articles on Leonardo’s theory of vision and pictorial perspective, and on his work in physiognomy, anatomy, botany, water science, and technology. -
Leonardo da Vinci. The Notebooks of Leonardo da Vinci. Edited by Irma Richter. 1939. New ed. New York: Oxford University Press, 1980. The best succinct introduction to the wealth of material contained in Leonardo’s notebooks. This text was originally published in 1883 as The Literary Works of Leonardo da Vinci and was edited by Jean Paul Richter. -
Letze, Otto, and Thomas Buchsteiner, eds. Leonardo da Vinci: Scientist, Inventor, Artist. Ostfildern-Rit, Germany: Gerd Hatje, 1997. The catalog for an exhibition on Leonardo da Vinci in Germany with sumptuous copies of painting and pages from the notebooks, along with brief discussions and an outline of his life. -
MacCurdy, Edward. The Notebooks of Leonardo da Vinci. New York: George Braziller, 1939. A massive translation of the texts of about five thousand folio pages, which includes biographical information about Leonardo and a history of the notebooks. -
O’Malley, Charles D., and J. B. de C. M. Saunders. Leonardo da Vinci on the Human Body: The Anatomical, Physiological, and Embryological Drawings of Leonardo da Vinci. New York: Henry Schuman, 1952. An extensive presentation of Leonardo’s anatomical drawings with translations of the accompanying descriptions. -
White, Michael. Leonardo: The First Scientist. New York: St. Martin’s Press, 2000. A nontechnical biography focusing on Leonardo’s scientific and technical notebooks and details of his personal life.
1495-1497: Leonardo da Vinci Paints The Last Supper
1543: Copernicus Publishes De Revolutionibus
1543: Vesalius Publishes On the Fabric of the Human Body
1553: Servetus Describes the Circulatory System
1572-1574: Tycho Brahe Observes a Supernova
1580’s-1590’s: Galileo Conducts His Early Experiments
1582: Gregory XIII Reforms the Calendar
1600: William Gilbert Publishes De Magnete