these wonderful images are curated by Erik Baker, he regularly shows series of images that he finds interesting and posts them on Design Observer . The posts always starts with a phrase "Here are Today's images". Some images from his posts are from established and widely known artists while some (i think more) of them are lesser known and date way back before our grandparents were even born. Here are the lists of series of his posts dating back on his first.
Click on the images below and they link to their original websites. however, a couple of them are not linked due to technical problems. sorry! :S