About 2.6 million historic photographs and illustration from books have been uploaded on Flickr by a single user, according to The Wire.

Georgetown University scholar Kalev Leetaru said he uploaded the images on the poplar site so people can access them for free. The photos and drawings were scanned by the Internet Archive organization from over 600 million books from libraries.

"Most of these 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," he said.

According to Leetaru, many libraries have begun digitizing their collection and converting them into PDFs. Since these files are mainly focused on text-based works, he decided to create a public collection that will solely feature images.

"For all these years all the libraries have been digitizing their books, but they have been putting them up as PDFs or test searchable works," he said. "They have been focusing on the books as a collection of words. This inverts that."

Leetaru's collection of images came from books published from the copyright-free period of 1500 to 1922. Scanning through the images, he said viewers will feel like they're traveling through time, PC Mag reported.

"I think one of the greatest things people will do is time travel through the images," he explained. 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 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," he added. "Then you see its evolution as it becomes part of everyday life."

Each of the images uploaded by Leetaru has been tagged with keywords to make them easy to search for. For an archivist, this is an impressive feat considering the vastness of the collection, according to BBC.

"Finding images within texts and tagging large collections of images are notoriously difficult," University of Cambridge's senior archivist Dr. Alison Pearn said.

"This is a clever way of providing both quantity and searchability, and it's great that it is freely available for anyone to use," she added.