Screws, rivets, ball bearings, pins, axles, couplings, belts, chains, gears, flywheels, levers, rods, ratchets, brakes, pipes, pistons, valves, springs, cranks, cams, pulleys.
I have just spent an afternoon perusing again Leonardo da Vinci's Notebooks, or facsimiles thereof. Anyone with an interest in engineering cannot turn these pages without pleasure. What an explosion of ingenuity! A mind racing pell-mell through an encyclopedia of mechanical contrivance, moving at such frenetic speed that application gets left in the lurch. Everything is conceived; nothing is built.
Anatomy. Hydraulics. Optics. Architecture. Aeronautics.
Paralyzed by genius. An unquiet mind. A mind so teeming with possibilities that nothing becomes possible. At the end of his life the catalog of his accomplished works is slim indeed.
A mind bewildered by contradictions. For every delicate wildflower among his drawings there are sketches of violent storms, explosions, and turbulence. For every beatific madonna and child there are men and animals locked in mortal combat. He bought birds from cages in the market so that he might free them, and then went home and drew horrible weapons of war -- spinning scythes surrounded by dismembered bodies, bombards raining fire, and shells exploding in star-bursts of shrapnel.
Freud's psychological essay on Leonardo is one of the most interesting things the Viennese psychiatrist ever wrote, but I never thought it explained very much. Leonardo's head was bursting with so many roiling, endlessly-fragmenting, colliding ideas that I doubt if the quintessential "Renaissance man" understood himself.
In 1516, at age 64, he was invited (as a trophy of war?) to France by the French king Francis I, who had recaptured Milan, and who liked and admired Leonardo. He was given the use of a grand house, the Chateau du Clos-Luce, a short walk away from the king's own palace at Amboise in the valley of the Loire (I have labeled the chateaux on the Google Earth image below). Here Leonardo lived out the final three years of his life in the company of his young student and friend, Count Francesco Melzi.
I like to imagine him there, bundled up in a thick robe by a roaring fire, locked in reverie. His body is weakened by the illness he had contracted in Rome, but his mind is still alert. The flames dance, his eyes roam the flickering shadows. He is overwhelmed by melancholy, wondering at how little he has to show for so long a life. Only three of his paintings accompanied him to France, including the Mona Lisa (of which more tomorrow). Of course, there is the vast trove of drawings, the record of a lifetime of insatiable curiosity, which will devolve upon Melzi at Leonardo's death, the majority of which will subsequently disappear.
But enough remain to confirm his genius. What was his contribution? A few simple but important truths. Looking is the basis for knowing. Behind nature's apparent turbulence there are fixed mechanical laws. The anticipation of nature is a fraud.