Look, An Octopus!

My life suddenly got better when I realized that Wikipedia is loaded with photographs and diagrams that are in the public domain. The free open-content encyclopedia is a source of thousands of images that one can use free of charge to enhance personal or work-related projects without having to worry about copyright laws.

Check out this free, public domain picture of Otto Lilienthal and his early attempt at a heavier-than-air flying machine: