Lately I’ve been thinking a lot about Leonardo da Vinci. Over the holidays I went up to New York to see the Codex Leicester, a notebook in which Leonardo recorded observations and theories about water -- about how it behaves and how it can be controlled. As a long-time fan of canals, dams, bridges, and other water-related projects, I was interested to know more about one of history’s most famous hydraulic engineers.
But I wasn’t prepared to be flat-out astonished by the genius of someone who died 478 years ago, when the textbooks were still those of antiquity -- Leonardo taught himself Latin to read translations of Aristotle, Euclid, and Ptolemy -- and when science was emerging from centuries of slumber. Nor had I understood the breadth of his interests: He was also an expert anatomist, a sought-after military engineer, a self-taught physicist, and, of course, one of the world’s best-known painters.
Among other water-related projects, he drew up plans in 1503 to rechannel the Arno River and make it navigable as far as Florence, an endeavor that would have been one of Europe’s marvels if it had ever been undertaken. Later, living out his last years in France, he proposed to connect the Loire and the Saone with a canal. In between, he studied almost every aspect of water, from how waves break against one another to how springs appear near the tops of mountains. Even in our own age of wonders, it makes a person stop and think.
The 72-page codex, which was recently exhibited at the American Museum of Natural History, is now owned by Microsoft founder Bill Gates, who bought it from the estate of Armand Hammer. It is believed to date to about 1508, when Leonardo was in his fifties, and it is chiefly a compilation of materials for a book about water that he never got around to writing. His notes range from precise observations of river currents and erosion patterns, carefully illustrated, to speculation about the sea that he was certain covered the surface of the moon. For good measure there are notes on planetary motion, physics, the makeup of the earth, and the mysteries of fossils, which vexed him: Why, he wanted to know, were"oysters and shells and sea snails and scallops and bones of great fishes ... found in many places on the high slopes?”
In fact, he wanted to know everything. At first, apparently, this was because he needed to understand how things worked in order to paint them. After that, as my 1944 Encyclopaedia Britannica puts it,"there grew upon him the passion of knowledge for its own sake.” The book on water was to have been part of a series explaining the workings of the cosmos, which Leonardo hoped to comprehend by observation, logic, and argument.
The pages are marvelous to look at. Many are filled with drawings and diagrams and plans for machinery and experiments. These occupy a wide right-hand margin, often intruding into the text. It takes a drawing that runs all the way across one page to illustrate his theory that"veins” from the bottom of the sea feed springs high in the mountains.
The text itself, however, is another matter. It’s in 16th-century Italian, for one thing. For another, Leonardo wrote in a tiny mirror script that runs from right to left, either because he was left-handed and didn’t want to smear the ink, or because writing backwards was his way of protecting his intellectual property in an era before copyright. The exhibit at the natural-history museum made the pages accessible by lining the room with terminals on which visitors could look at a CD-ROM version of the codex produced by the Corbis Corporation, which Mr. Gates also founded. The CD includes a graceful English translation and a synopsis of each page, with explanations of Leonardo’s denser arguments and background information about Renaissance understandings of physics.
In a way, his notes are just as interesting as a finished book would have been, because they show you how he approached the mysteries of his age. You recognize a boy’s relentless curiosity, never dulled or stifled, that combined with a scientist’s determination to review every case methodically and to derive general principles from what he had seen. In his drawings, meanwhile, you recognize an eye so keen that it could see in detail what your own cannot -- how a drop of water deforms as it splashes into a basin, or how currents swirl around bridge piers. His notes on siphons, for example, consider and illustrate not just simple examples but also the rare cases: siphons narrower at the upper end than at the lower and vice versa, siphons that begin as single tubes but divide into two, siphons that divide into tubes of unequal lengths. Following the step-by-step advance of his logic is a rare privilege.
Some of what he believed to be true was not, of course. The earth was not the center of the cosmos, as he and most of his contemporaries supposed, nor was the moon covered by water, although Leonardo’s reasons for supposing so make perfect sense. And much of what he taught himself was both accurate and entirely new. He not only asked questions that no one else would have thought of, but found answers as well. In many instances his analyses anticipated by a hundred years or more the advances of knowledge on which modern science is founded.
The great irony is that Leonardo never published any of his findings, never really contributed to those advances. Almost all of what he discovered for himself had to be rediscovered by others later on. It’s hard to read his notes without thinking of that, without wondering what this amazing man must have been like to know -- and without wishing you could lead him through the rest of the museum. The galleries filled with dinosaur skeletons and the room full of meteorites and the exhibition on the human body -- how they would fascinate him! What would he make of Darwin? Of the fragment of rock brought back from the moon? Of retroviruses?
As it happens, another artifact of Leonardo is closer at hand, an early painting called Ginevra de’ Benci that was acquired some years ago by the National Gallery of Art here in Washington. On a busy holiday weekend I found it in a nearly deserted basement room, surrounded by works of Botticelli and Fra Filippo Lippi."A rather dull, expressionless Verrocchiesque portrait of a young woman with a fanciful background of pine-sprays,” my Britannica sniffs, but I disagree. You must let your eyes accustom themselves to its muted palette, which seems almost colorless beside Fra Filippo’s piercing blues. And then stand close -- two feet away, or even one -- and take your time looking. Ginevra’s skin becomes so soft, her expression so delicate and natural, that you see why Leonardo’s paintings haunt the memory. His eyes, like his curiosity, were unsurpassed.
You wonder, too, what the painting remembers: Does the canvas recall what they talked about, the artist and his young subject? Do the colors remember Leonardo’s touch, his finger wiping away a drip or smoothing a pale cheek? Can they still feel his gaze, sharper than any they have ever felt since? Can we, if we look hard enough, see through them, and through the notebooks, into Leonardo’s mind? Surely more waits there to be rediscovered.
