But there's something else that Pascal Cotte believes he has confirmed after peering through the 1, layers of varnish and oils that make up the world's most-famous painting. It's the largest exhibit ever mounted by the museum, with more than pieces sprawling through several upstairs galleries. The displays — some set up for touch-screen browsing — reveal many aspects of the life of the Italian painter, sculptor, writer, architect, musician, mathematician, engineer, anatomist, geologist, mapmaker, botanist and obsessive note-taker. Leonardo da Vinci was also an inventor, but he never took his designs beyond his notebooks, reproduced for the exhibit in exacting detail. There is the famous augur-sailed helicopter, and a model of his "Ideal City.