April 15 Not Just Taxes

Some think of today as synonymous with taxes. It's the birthday of a brilliant man who had a hard time finishing things, Leonardo da Vinci, born in the Republic of Florence (1452). Though he lived for 67 years, only 17 of his paintings are known to exist, and only a few of those were finished to his satisfaction, including The Last Supper and Mona Lisa.

He kept notebooks full of ideas about architecture and technology of all kinds. Even the doodle pictures of parachutes he drew in the margin of his notes turned out to be technically perfect designs. He drew up plans for an assault battleship, a construction crane, a trench-digging machine, a revolving bridge, and a deep-sea diving suit. He made architectural sketches of churches that looked like seashells or blossoming flowers, none of which got built because they were too impractical. Most of his ideas were too ambitious for the tools that existed at the time.

In 1482, Leonardo began a sculpture of a horse. It was extremely difficult to design because the final product would weigh many tons when cast in bronze, and Leonardo wanted the horse to be rearing back on its hind legs. He spent 11 years sketching out the solution to the problem of the horse's balance, but when he tried to cast the horse in bronze, he found that all the bronze in the city had been used to build cannons for an impending war. So the sculpture went unfinished until 1999, when a Japanese-American sculptor used Leonardo's drawings and plans to build the horse. The finished product was 23 feet high, weighed 15 tons, and was perfectly balanced. For the rest of the story see The Writer's Almanac on this day.