This is the cover of the October 1948 issue of Amazing Stories, which some neglector of intellectual property has prematurely let fall into the public domain. Project Gutenberg has a bunch of amazing artwork and history like this that you might find with a search of [science fiction covers].
I love the teaser for the featured story, The Brain: “A Giant Calculating Machine Decides To Rule The world!” A calculating machine! And it has decided to rule the world!





