'Above all, the mirror is our teacher'

The museum is full of recent, mostly working, models of da Vinci's conceptions including several quite sophisticated mirror-polishing machines.

The quote in the headline above is by Leonardo da Vinci, the famous Italian Renaissance scholar, artist, and engineer. I came across this intriguing quote at the beginning of a chapter in a fascinating book, Mirror, Mirror: a History of the Human Love Affair with Reflection, by Mark Pendergrast (Basic Books, New York, NY; 2003). The author notes that the artists and scholars of the Renaissance were often influenced by the reflections of mirrors.

I was reminded of Filippo Brunelleschi, the architect of the famous dome of Florence's huge cathedral, who conducted an experiment with a mirror that blended reality with a reflective image. One of the earliest artists to work with perspective, Brunelleschi painted a reversed picture of the doors of the octagonal Baptistery of San Giovanni that had to be viewed in a precise location at a particular time of day. Brunelleschi drilled a small hole in the picture at the "vanishing point," and asked viewers to look through the back of the picture while holding a mirror in front of it. The result was an image that was re-reversed and so appeared as in reality.

With this neat visual trick, viewers could not distinguish illusion from reality. Brunelleschi's early experiments with mirrors and perspective are described in more detail in Ross King's excellent book, Brunelleschi's Dome, (Penguin Books, New York, NY; 2001). Unfortunately, the original painting has long since disappeared, but there are other examples of Brunelleschi's work with perspective in the Florence cathedral museum (Museo dell'Opera del Duomo).

If you are interested in seeing more of Leonardo da Vinci's experiments, you could visit the unique Leonardo da Vinci museum in the tiny town of Vinci near Florence, or you could take a tour of the museum by visiting the informative website (www.leonet.it/comuni/vinci/). The museum is full of recent, mostly working, models of da Vinci's conceptions including several quite sophisticated mirror-polishing machines. I mention this because Leonardo left his extensive notebooks which today give us a detailed picture (no pun intended) of his use of mirrors.

In fact, Leonardo wrote much of his notebook descriptions in mirror writing and, indeed, examined his paintings critically with mirrors. He wrote, "When you wish to see whether the general effect of your picture corresponds with that of the object represented after nature, take a mirror and set it so that it reflects the actual thing . . . The mirror ought to be taken as a guide . . . If you but know well how to compose your picture, it will also seem a natural thing seen in a great mirror."

But don't let me give you the impression that Pendergrast's book is overly concerned with fine artists and their use of mirrors. The book is an extensively researched review of mirrors and reflected light through the ages from the discovery of the first artificial mirrors in Turkey around 6200 BC to the contemporary experiments with micromirrors and microelectromechanical systems (MEMS) at Bell Labs and elsewhere. As a scientific historian, Pendergrast has researched his subject thoroughly and presents a wealth of detail that is, at times, quite overwhelming. He also includes extensive notes on his sources, leading to further avenues of exploration for the interested reader.

For example, I had never heard of the "mirror-maze." Pendergrast mentions two such mazes, one in Lucerne, Switzerland and one in Prague, Czechoslovakia. He even finds a modern mirror-maze architect, Adrian Fisher, in England, who says, "The whole thing about a mirror maze is to create a surreal experience, entering what you know is a small space that feels five times larger." If you'd like to know more, consult Fisher's fascinating web site (www.mirrormaze.com/mirror_mazes_worldwide.htm).

So Leonardo da Vinci was right, the mirror is our teacher and Mark Pendergrast's book is an excellent mirror to the many reflections of light.