Not wanting to set a precedent by pointing to sites where the book collections are free and out of copyright, but the following is another example in the NZ Electronic Text Collection of an electronic copy of a book that is in copyright and readily available new in paper, but which the rights holder has authorised its availability.
http://nzetc.victoria.ac.nz//tm/scho...Bea04Cook.html (NB. The site is currently very slow, still recovering from Christmas celebrations, perhaps?)
This is J. C. Beaglehole's
Life of Captain James Cook and is the gold standard detailed Cook biography and it covers, of course, his visits to Australia and New Zealand.
As well as the online version it is available for download in epub (halfway down right hand side of page under "Other Formats") but as is typical for this site the epub is set out in a manner more appropriate to researchers and PCs or tablets.
In my own case, and even though I have the paper book too, I have spent a couple of hours rebuilding the epub to be more suitable on small reading devices (for anyone prone to such flagellation I sometimes find that recovering the NZETC web page's HTML out of ones browser and then building an ebook from that is quicker and gives a better result).