From the newsletter of ANZMapS:
"The first two volumes of the defining work, The History of Cartography, are now freely available online.
That means four physical volumes, with the hope that the two-part Volume 3 may follow in the future.
The University of Chicago Press has broken the text down into the separate chapters, presented as a series of 104 pdfs. http://press.uchicago.edu/books/HOC/index.html
Not only can you search and download individual chapters, you can also search across the four volumes.
This is a major initiative, for which the publishers must be thanked and congratulated."
The museum I work for has purchased the books. The printed ones are really nice but I do believe someone does need a free version.