Unknown / Unknown Worlds

Launched by John W. Campbell, Jr., the pulp magazine Unknown was a fantasy companion to Astounding Science Fiction, also edited by Caampbell. Unknown first appeared as a monthly in March 1939, switching to bimonthly in February 1941. In October 1941 the magazine title was changed to Unknown Worlds, and the magazine was changed from a standard pulp format to the larger bedsheet format. Due to wartime paper shortages, Unknown Worlds returned to the pulp format in June 1943. and ceased publication in October 1943. Early issues of Unknown had cover paintings; beginning in July 1940, the covers showed a table of contents.