Leonardo's Atlantic Codex, on Display at the Biblioteca Ambrosiana in Milan

This looks fascinating:

The Biblioteca Ambrosiana, which opened as one of Europe's first public libraries in 1609, would rank as a major tourist attraction in almost any other country. Its art gallery features paintings by Leonardo, Botticelli, Titian, Caravaggio and the full-scale "cartoon" (or preparatory drawing) for Raphael's monumental fresco of "The School of Athens" in the Vatican Museums.

At least as precious, but ordinarily visible only to scholars, is the Ambrosiana's collection of manuscripts and rare printed books. Holdings include a fifth-century illuminated copy of Homer's Iliad and a 14th-century edition of the works of Virgil, with hand-written annotations by the Renaissance poet Petrarch. Yet no item in the library's possession can be more intriguing to experts and laymen alike than Leonardo's Atlantic Codex.

With 1,119 pages of drawings and notes, almost all of them in Leonardo's own hand, the Atlantic Codex is by far the largest set of works by the archetype of universal genius. Leonardo's more famous Codex Leicester, currently the property of Bill Gates, is only 72 pages long.

Clearly the work of a lifetime but, still, at 1,119 pages, Leonardo was not only a genius but a hard worker. Which should serve as a lesson to the talented - of which, I'm not one, alas: talent without hard work is meaningless. You gotta get up every day and put in the work.