This from the usually forward looking site io9, "A historian has reconstructed the lost library of books that accompanied Charles Darwin during his five-year scientific voyage across the world, allowing the public to read the more than 400 volumes that served as reference and inspiration for the young naturalist whose theories would revolutionize biology.
The library was dispersed at the conclusion of the voyage. But now, nearly 180 years later, it has been electronically reconstructed in its entirety by historian John van Wyhe and is freely available at his Darwin Online website. The collection consists of more than 195,000 pages containing over 5,000 illustrations."
Here's the link to the Charles Darwin Beagle Library