In looking through some early Worldcon program books earlier today, I came across these ads taken out for the Thrilling science fiction pulp line.  The Chicon 1940 one is by Hans Wesso; the Denvention 1941 one is by Virgil Finlay.  Leo Margulies of Thrilling had famously announced the pulp, “Captain Future,” at the first Worldcon in New York City in 1939.  These two ads kept alive the Worldcon – Captain Future connection.