Leonardo da Vinci (1452-1519) is well known around the world as an artist. Millions of people every year flock to the Louvre Museum in Paris, France, to get a glimpse of his painting the "Mona Lisa." His sketch of "The Vitruvian Man" changed the way people use proportion in art. His depiction of Christ and his disciples, "The Last Supper," even influenced the plot for the immensely popular best-selling book by Dan Brown, "The Da Vinci Code."
But Leonardo isn't called the ultimate Renaissance man without reason. He didn't just paint -- he was also a sculptor, an anatomy expert and an engineer, and he managed to predict the steam engine, the tank and the submarine.
During his 30s, Leonardo also took a great interest in flight, and by about 1505 had collected around 20 years of theory on flight. It is around this time that some think Leonardo built a complex ornithopter, a machine with flapping wings that closely mimicked the anatomy of birds.
No one really knows if Leonardo actually built a model of and tested his ornithopter. Many of his designs remained on paper during his lifetime and weren't built until much later; a working model of his primitive version of the car, for instance, wasn't actually constructed until 2004 because of a misunderstanding of the sketches. In 1550, however, one of Leonardo's associates, Cardanus, wrote that he had tried "in vain" to get the ornithopter off of the ground, so there's a possibility that the Renaissance man took his machine for a few disastrous spins.
Some of Leonardo's contemporaries couldn't quite figure out how to get off the ground, either. To learn about two of them, read the next page.