Kalev Leetaru interviewed for BBC:
"Stretching half a millennium, it's amazing to see the total range of images and how the portrayals of things have changed over time.
"Most of the images that are in the books are not in any of the art galleries of the world - the original copies have long ago been lost."
The pictures range from 1500 to 1922, when copyright restrictions kick in.
The images are actually quite good. I could easily get lost in the archive on Flickr for hours.
"Type in the telephone, for example, and you can see that all the initial pictures are of businesspeople, and mostly men.
"Then you see it morph into more of a tool to connect families.
"You see another progression with the railroad where in the first images it was all about innovation and progress that was going to change the world, then you see its evolution as it becomes part of everyday life."
It is great to see this resource has come together. For the love of content creation, the world needs more curators like Kalev. ∞