By: Alan Riding

The New York Times, September 26, 2006

ONDON—The 6,000 or so extant pages of text and drawings attributed to Leonardo da Vinci are thought to represent only about one-fifth of his output. Yet, remarkably, in a new show at the Victoria and Albert Museum here, just 62 yellowing sheets suffice to illuminate the endlessly curious and inventive mind of this quintessential Renaissance man.

Strictly speaking, the show, ''Leonardo da Vinci: Experience, Experiment and Design'' is not an art exhibition: many of the pages of sketches and mirror writing are more intriguing than beautiful. Rather, the display, which runs through Jan. 7, sets out to explore how Leonardo used paper to brainstorm about the mysteries and mechanics of life. And it reveals him to be an early master of lateral thinking.

In one dimly lighted gallery, the man best known to the world as the painter of Mona Lisa and ''The Last Supper'' (and as Dan Brown's inspiration) shows himself also as a scientist, engineer, architect, mathematician, weapons designer and medical researcher. For him, though, these were not competing fields: they were all subject to the universal rules of nature.

Take ''Theme Sheet,'' the name given to one of the first displays: it tackles no fewer than 16 different subjects, including various geometric designs, a man with a ''Roman'' profile, a rearing horse, a bell tower, strands of curly hair, a tree and two stems. And other sheets similarly suggest a man who is recording his thoughts and observations as he goes along.

Selected to underline this restlessness of mind, the pages and notebooks in the exhibition come from the Victoria and Albert's own collection, as well as from those of the British Library, the British Museum and the Royal Collection at Windsor Castle. And if Leonardo himself believed that all of nature was contained in a particle, this sample is a microcosm that illustrates the whole. (Bill Gates refused to lend the notebook known as the Codex Leicester after disagreements with the museum over lighting and security, The Art Newspaper reported.)

It goes without saying that like his younger peer Michelangelo, Leonardo was a fine draftsman. But this show, which comes a few months after an excellent exhibition of Michelangelo's drawings at the British Museum, also highlights how these two great artists differed in their approaches to works on paper.

Michelangelo used drawings to prepare his paintings, sculptures and architecture, then ordered the papers' destruction as he was dying, as if the need for these studies diminished his genius. In contrast, drawing for Leonardo was both a tool of his scientific investigation and proof of his achievements: he protected his sheets of paper by binding them in notebooks.

Still more strikingly, while Michelangelo captured the movement and muscularity of bodies, not least in his studies for the Sistine Chapel, Leonardo went literally inside bodies to learn how they worked. (At one point he remarks on the unpleasantness of dissecting corpses.)

Everything, it seems, interested him. One large sheet contains 11 studies of an ox's heart, as well as several details of it, with particular attention to its atria and ventricles, illustrations that medical researchers have since proved to be accurate. From his analysis of the heart's one-way valve he was able to design mechanical valves for other purposes.

By dissecting a human arm and a bird's wing, he explored what form of artificial wing would be necessary for man to fly. ''When he realized that humans cannot get off the ground,'' said Martin Kemp, the Oxford University professor who organized this show, ''he became more interested in a gliding machine than a flapping machine.'' (Models of his flying machine and of his parachute hang in the museum's entrance hall.)

There are many other examples of Leonardo's fascination with the parallels between nature and human physiology. He writes of the body as a ''tree'' of blood vessels and imagines oceans ''breathing'' in and out their tides. One striking sheet shows a rearing and neighing horse in various postures and accompanies these studies with drawings of a man and a lion similarly roaring.

Persuaded that vision—''sapere vedere,'' or ''knowing how to see''—was the most valuable sense, on another page he portrays—or, rather, speculates—how the brain receives and interprets what the eye captures. And here he draws an onion to suggest the supposed layers of the brain.

In looking for order in life, he examined proportions, demonstrating—as Vitruvius had done before him—that a human figure standing with legs apart and arms extended fit equally into a square and a circle. These explorations are complemented by his many geometric studies, which are cleverly illustrated in one of several animations developed for this show.

What won Leonardo a place in Ludovico Sforza's court in Milan as ''painter and engineer of the duke'' was his ability to turn theory into practice. While he described war as ''beastly madness,'' he nonetheless portrayed its fury in his unfinished fresco of ''The Battle of Anghiari'' and even developed weaponry, including a large crossbow, chariots and even something resembling a rudimentary tank.

His extensive investigation into the behavior of water led to his work as a hydraulic engineer, which ranged from unrealized plans to build a canal from Florence to the sea to his later construction of a large, water-driven clock.

His research into mechanics, in turn, enabled him to understand friction and resistance, knowledge he used to develop gearing systems. One page in this exhibition presents his stage design for a production of ''Orfeo'' in which a mountain opens up mechanically to expose Pluto's underworld. But even Leonardo abandoned attempts to create a machine of perpetual motion.

So how much did Leonardo get right?

''He wasn't a Galileo or a Newton, but there was a fundamental rightness to his approach,'' Mr. Kemp explained. ''This shows what a human mind is capable of.''

And of course Leonardo was capable of much more, as is demonstrated by an initiative called Universal Leonardo, which is overseeing a series of exhibitions—focusing on different aspects of his genius—through January in Florence, Oxford, Munich, Milan and London.

The program's premise is that rather than endanger fragile artworks by organizing a single blockbuster, it is wiser to put together smaller shows built around the Leonardo collections in different cities. It is Britain's good fortune to have had 19th-century collectors who understood the value of his works on paper.