by Academician Konstantin FROLOV, Director, A. A. Blagonravov Institute of Engineering, Russian Academy of Sciences
Leonardo da Vinci (1452 - 1519), the great savant, inventor and artist, symbolizes victory of the human mind over medieval dogmatism and scholasticism. He pioneered in a new vision of nature as an object of research and, by enriching every field of knowledge of his day, anticipated many discoveries centuries ahead.
Leonardo was born at Vinci, Italy, a town lying between Florence and Pisa. He was an illegitimate son of a notary, the father of a large family. At age 14 the boy was taken to Florence and placed in the workshop of Andrea del Verrocchio, goldsmith, sculptor and painter. While staying in Florence, Leonardo learned, besides painting and architecture, the fundamentals of mathematics and mechanics. In subsequent years, the studious young man perused the works of Aristotle, Archimedes, Heron, and Euclid; he delved into other writings as well, be it astronomy, scientific discoveries of the Arabs, or oriental wisdom. The inquisitive youth also met the famous men of his time, like Donato Bramante, architect, Luca Pacioli, mathematician, Fazio Cardano, engineer, and other celebrities.
The Italian Renaissance was a congenial settling for Leonardo's multifarious interests and talents. Raised in a poor family, the youth was averse to the haughty airs of his "highborn" agemates, and he embraced with much elan the ideas of humanism whereby the only yardstick and measure of one's merit was personal dignity and education, not the birthright nobility.
The need of practical activity for society's good became obvious in those buoyant, fitful days. Scholars would not put with their role of text interpreters, they were eager to become creators in their own right, free from the corporative spirit of university or religious order members. Such moods brought about a dramatic turn both in the subject-matter and in the methods of natural sciences, and set the stage for classical mechanics, where theoretical disquisitions were relegated to a secondary place.
Leonardo da Vinci was one of the first among his contemporaries to understand all that. He gave himself up to studying such matters as a body's motion on an inclined plane, purchase (leverage) laws, hydrostatics, free fall, the phenomenon of force and its definition, etc.
During his stay in Florence, the young prodigy mastered the basics of the textile industry (that city enjoyed the fame of being a major textile production center) and turned to designing twist lathes. While still in Florence, Leonardo devised the mechanics of looms, he designed these machines and parts to them. Leonardo da Vinci sought to achieve an optimal level of mechanization of laborious production processes in the textile business.
At age 30 Leonardo da Vinci left Florence for Milan where he remained as a member of the ducal court, preparing sets and costumes for revels. Joining the local collegium of engineers, he made the grade as a weapons designer; he also drew up plans for buildings, and worked on the construction of canals and waterways. Besides, he showed talents in machinery designing. Leonardo went
on with his creative work in Florence, Rome and then again in Milan, overrun by the French by that time.
Leonardo developed a special interest in mechanics which he viewed as the key to many mysteries of the universe. He authored outstanding works on the basic laws of statics, motion and inertia, and on friction, elasticity, and so forth. His passionate involvement with modeling and experimenting prompted great design solutions that went centuries ahead of the Renaissance age. For instance, Leonardo made sketches and drawings of melting furnaces and rolling mills, he designed printing, wood- working, earth-moving and other machines. He went as far as to sketch down shorthands of a submarine and a tank!
Quite apt in the art of experimenting, Leonardo was able to explain the whys and wherefores of his inventions-in theory, too. While designing pretty sophisticated machines, Leonardo the engineer had to develop a theory of gearing and attack the problem of its kinematics at variable rotation rates. He sought to make transmissions with flexible gears. His sketches and drawings show a variety of such gears, down to spiral wheels and hour-glass worms. He was the first to design skew and bevel gearings. In addition, Leonardo took to studying an articulated-link (pintle) chain and other mechanical items of this kind, and addressed problems related to strength of materials, friction and mechanical wear. His interests extended also to engineering hydraulics and the theory of elasticity.
Leonardo da Vinci has made an enormous contribution to the science of machines. His intellectual legacy, making up something like seven thousand texts and drawings (with many being still an enigma to us!), is an impressive inventory of great insights and discoveries. Even a mere list of them will take reams of paper. Still, it would be in place to mention at least some of his projects attesting to the great scope of his multidimensional personality.
If we take mechanics, these are fixed-ratio transmissions, printing presses, roller bearings, bevel screws, composite chains, and wood-working machines; add to this a paraboloid compass, instruments for wind velocity and water pressure measurements. Also, windmills with a single tumbling barrel, single-wheel barrows, rivet-making machines, gold-expanders, stamping and coining lathes, and high-performance textile looms and lathes. If we take hydraulic engineering, these will be a hydraulic press, a centrifugal pump, a screw water hoist, a bucket dredge, and a pump pendulum. If we take weaponry, these are a rifled gun, a pistol fitted out with a drum (cylinder), a cannon loaded from the breech end, a steam gun...
All through his lifetime Leonardo kept designing flying vehicles. To begin with, he strove to understand the bird flight-how birds soar, hover and land. He studied the anatomy of their flying organs, their flight kinematics and dynamics. In the end the air-minded inventor conceptualized the idea of what we call bionics today: the effect of wing and tail motions, and of the center of gravity position on the flight mechanics. Leonardo's manuscripts are dotted with drawings of sundry aircraft. His design of a swing-plane anticipates the now classical technical solutions like the slewing tail unit (empennage), the streamlined fuselage in the shape of a boat, and the retractable landing gear.
In the notebooks and drawings left to us by the famous Italian, we can see different types of aircraft wings. He even conceptualized a propeller but, for objective reasons, was unable to make an engine with a thrust powerful enough for overcoming the force of gravity.
Seeing that a primitive swing-plane was no good for air flights, Leonardo revolved the idea of a wind-driven flying machine. He designed an ornithopter with a wing having the slow-moving central part and the more mobile flaps for flight control.
Leonardo da Vinci even attempted to design a helicopter. Some of the notes to his drawings are coded, both in the hand-writing style and in technical terminology.
The great inventor also designed a rocket prototype (this design is displayed in the Kaluga-based museum named after Konstantin Tsiolkovsky, one of the masterminds of space flights).
Leonardo da Vinci also did much in designing building-industry machinery, for one, the tower crane for hoisting cargoes.
Fortification was another field of his application. Leonardo drew up a plan for building a bridge operated by a rather original mechanism placed underground. That was very important for Italy with its mountainous terrain posing great problems for bridge and road building.
His projects of canals, waterways and irrigation ditches are likewise remarkable. Leonardo carried out quite a number of experiments in this field. This enabled him, among other things, to make an adequate description of a liquid's equilibrium in communicating vessels and forecast some of the laws of hydrodynamics. His drawings, graphs and diagrams show water in all its forms of movement. He gave practical recommendations for erecting dams with due account of the water flow and pressure.
Leonardo da Vinci has made a signal contribution to natural sciences, astronomy, for one. Extending terrestrial laws to celestial bodies, he well-nigh conceived a heliocentric picture of the solar system, and could explain in cogent terms why the moon is of ash-gray color. Simultaneously, he showed interest in free fall and related experiments.
Physics was also his forte-in particular, oscillations as visualized in the theories of sound, light, heat and magnetism. Heat and combustion was yet another line of his research.
Leonardo did a remarkable lot in studying man's anatomy, the skeleton and muscles in particular. He undertook this work while living in Rome. But then came slanderous denunciations addressed to the Pope and the chief of the hospital in which Leonardo doing was his anatomical studies based on dissection. In the end, he was banned from carrying on further studies in this field.
Leonardo da Vinci thought centuries ahead of his time, and his grandiose projects were out of keeping with the tenor of his time. And yet he managed to bring practical
experience into a system of scientific knowledge in mathematics, physics, biology and botany, in anatomy and other sciences.
All through his life Leonardo would take notes on what he saw and thought, often supplementing them with brilliant sketches of his inventions. A drawing-scientifically elegant, rational in its engineering conception and perfect artistically-was his working tool. He made no use of a draftsman's paraphernalia and was equally good in using both his right and his left hand. Whatever he drew was infused with exceptional, true- to-life harmony.
The great Italian saw painting as the finest instrument for man to comprehend the world he lived in, fostering imaginative, creative thinking. Pictorial arts, being a universal method of cognition, helped Leonardo to form a multidimensional vision of the surrounding world and view it as an orderly, harmonious whole in the maze of odd and haphazard phenomena, with man as the crown of creation.
All this is exemplified in Leonardo's immortal paintings, such as ADORAZIONE (Adoration of Christ by the Magi; Florence, Galleria degli Uffizi), LA VERGINE DELLE ROCCE (MADONNA IN THE GROTTO; Paris, Le Louvre) and finally, his famous work L'ULTIMA CENA (THE LAST SUPPER), a mural painted on the wall of the monastery church Santa Maria delle Grazie. In it we see the maestro's striving for the same rationality of composition (figures of the Apostles as an integral part of conceptual design) as in his scientific and engineering inquisitions.
The Mona Lisa (LA GIOCONDA; ca. anno 1503, Le Louvre) is certainly the acme of Leonardo's artistic creations. Legend has it she was married to Francesco del Giocondo, a Florentine nobleman. The young lady embodies the humanistic ideal of womanly charm and pulchritude. Her enigmatic smile conceals a wealth of subtle feelings and emotions, and reveals a lofty nobility of spirit. This portrait has become a symbol of Leonardo's age.
Leonardo da Vinci was deeply conscious of the orderly scheme of things in the universe, and believed in the boundless might of human reason. His motto was, "Better death than fatigue", and he was true to it as long as he lived. Leonardo's immense creative heritage is alive in his canvases, notebooks and in his handiwork; this is a wellspring of knowledge, sublime humanism and ethical values prodding us to tell good from evil.
The monument to Leonardo da Vinci in Milan kind of airs this message to his offspring: Watch, learn and perpend; and create, but think what you create! We must know how to see and observe: "Bisogna saper vedere."