The 1910 autochrome of medieval cosplayers, cropped above, and the monkey-on-a-rhino gelatin print below are in a set of early 20th century photographs from The George Eastman House, which has joined the flickr commons. I spotted this on photographer Raul Gutierrez' blog (a regular source of joy for me), and there he wrote:
Flickr Commons is a fantastic idea. My wish is that the whole thing could be taken further. Imagine an open source version of flickr dedicated to showing artwork and photography from public institutions in which users had the opportunity to contribute scholarly work or to group images into collections.
George Eastman House's photostream [Flickr]