In this volume the author describes more than 3000 short stories, novels, and plays with science fiction elements, from earliest times to 1930. He includes imaginary voyages, utopias, Victorian boys' books, dime novels, pulp magazine stories, British scientific romances and mainstream work with science fiction elements. Many of these publications are extremely rare, surviving in only a handful of copies, and most of them have never been described before.

Volumes for 1898-1968 include a directory of publishers.