The Great God Pan
What is now the first chapter of the novella was published in 1890 in a magazine called "The Whirlwind", while what is now the third chapter of the book was published in the same magazine the following year as a standalone short story called "The City of Resurrections". Machen only viewed the two works as connected after they were finished. Once he decided the two stories were connected, Machen wrote the rest of "The Great God Pan" in a single evening save for its final chapter. Machen did not think of an ending for the tale for months, and in that time believed that the novella would remain unfinished forever. The last chapter was completed in June 1891. Machen sent the novella to the publisher Blackwood, who rejected it, deeming it a clever story that "shrink[s]...from the central idea." It was accepted by John Lane and published in 1894. When published as a book, "The Great God Pan" was accompanied by another Machen tale called "The Inmost Light" which also features a mad scientist and elements of science fiction. The book's cover was illustrated by Aubrey Beardsley.
New Worlds (magazine)
A US reprint edition of "New Worlds" ran briefly in 1960, published by Great American Publications, who at the time were the publishers of "Fantastic Universe", edited by Hans Stefan Santesson. The first issue appeared in March 1960; it omitted Carnell's name, and credited Santesson as editor. Although the fiction consisted entirely of reprints, with all but one story coming from the British "New Worlds", this was not declared to the reader. Carnell was unhappy with the results of this attempt to break into the US market, but in the event Great American collapsed later that year and only five issues appeared, on a monthly schedule from March to July. The contents of the issues did not correspond to specific British issues: the majority were taken from "New Worlds" but one story was reprinted from Nova's edition of "Science Fiction Adventures", and three were taken from "Fantastic Universe", which had ceased publication with its March 1960 issue.