Although science fiction (sf) had been published before the 1920s, it did not begin to coalesce into a separately marketed genre until the appearance in 1926 of "Amazing Stories", a pulp magazine published by Hugo Gernsback. By the end of the 1930s the field was booming, and several new sf magazines were launched in 1939. Frederik Pohl, a science fiction fan and aspiring writer, visited Robert Erisman, the editor of "Marvel Science Stories" and "Dynamic Science Stories", to ask for a job. Erisman did not have an opening for him, but told Pohl that Popular Publications, a leading pulp publisher, was starting a new line of low-paying magazines and might be interested in adding a science fiction title. On October 25, 1939, Pohl visited Rogers Terrill at Popular, and was hired immediately, at the age of nineteen, on a salary of ten dollars per week. Pohl was given two magazines to edit: "Super Science Stories" and "Astonishing Stories". "Super Science Stories" was intended to carry longer pieces, and "Astonishing" focused on shorter fiction; "Super Science Stories" was retitled "Super Science Novels Magazine" in March 1941, reflecting this policy, but after only three issues the title was changed back to "Super Science Stories".