2,619,833 copyright free images are available from the Flickr account of the Internet Archive Book Images.There
are another 10 million images (thereabouts) to go up into the
collection as well. They range from 1500 to 1922 when copyright law
kicks in. The images are varied - woodcuts, sheet music, advertising,
diagrams, a few photographs and so on. It's a fascinating collection and
worth taking a look at.
http://philbradley.typepad.com/phil_bradleys_weblog/2014/09/internet-archive-book-images.html
Thanks to Phil Bradley
