First Edition in book form, originally published as a three-part serial in ‘Astounding Science’. Original pale green cloth boards, edges slightly rubbed in places, a few mild spots to the spine, some patches of staining to the fore-edge. With the fully intact dust-jacket, unclipped, depicting a spaceman in full space suit standing in front of his craft with two boys who appear to have come across him while out hiking. Jacket rubbed at fold joints and spine ends. Scarce, especially in the dust-jacket, here found in remarkably good condition. Jacket designed by Ric Binkley (1921-68), an American artist about whom little is known other than he began painting covers for books for Fantasy Press and Gnome Press in 1950, working steadily for several years for those publishers and for Avalon Books, and then became inactive. He was both born and died in Wernersville, Pennsylvania. Harry Clement Stubbs (1922–2003), better known by the pen name Hal Clement, was an American science fiction writer and a leader of the hard science fiction sub-genre. He also painted astronomically oriented artworks under the name George Richard. In 1998 Clement was inducted by the Science Fiction and Fantasy Hall of Fame and named the 17th SFWA Grand Master by the Science Fiction and Fantasy Writers of America (presented in 1999).