Lieutenant Gullivar Jones: His Vacation is an escapist novel by Edwin Lester Arnold combining elements of both fantasy and science fiction, first published in 1905. The last of Arnold's novels, its lukewarm reception led him to stop writing fiction. It has since become his best known work, and is considered important in the development of 20th century science fiction in that it is a precursor and likely inspiration to Edgar Rice Burroughs's classic A Princess of Mars (1911), which spawned the sword and planet genre.