The Hathi Trust is a reliable and increasingly comprehensive digital archive of library materials converted from print that is co-owned and managed by a number of academic institutions.
Public domain works:
Anyone can view and download one page at a time. Users with a current University of Minnesota login can download the full work.
Copyright protected works:
Works protected by copyright will have limited access, except for users with print-reading disabilities who apply for special access to digitized works.
Additional information on accessing HathiTrust