My original tumblr post was here. This cover of Amazing Stories, probably illustrating “The Edge of the Knife” was first blogged by pulpcovers and comes to us via reginaldjuice.

My original tumblr post was here. This image of the Hugo Gernsback-edited Wonder Stories, possibly illustrating the story “The Robot Technocrat,” was first blogged by pulpcovers.com.

My original tumblr post was here. This image was first blogged on tumblr by magictransistor, who identifies it as “Frank R. Paul, Planet Of The Knob Heads (Stanton A. Coblentz), Science Fiction, 1939.”