to the Centre of the Earth (1959), based on a Verne novel, and made plans for two similar follow ups, The Lost World (1960), based on the novel by Arthur Conan Doyle, and Five Weeks in a Balloon. In June 1961, Irwin Allen, who had made The Lost World announced he had secured rights to the novel after six years of negotiation and would likely make the film at 20th Century Fox. The book was mostly in the public domain but was still in copyright in some countries. Allen wanted to release the film in 1962 in time for the one hundredth anniversary of the novel. In June 1961 Allen announced he had signed a multi-picture deal with Fox of which Balloon would be the first and Passage to the End of Space, an Allen original, would be the second. Cedric Hardwicke, who had just enjoyed a Broadway success in A Majority of One, was cast in the lead. Fabian, who had a long term contract with Fox, signed to play a support role. Another key role went to Red Buttons who, like Fabian, had just been in Fox's The Longest Day (1962). There was a race between two producers attempting to be the first to film the story: Allen and the Woolner Brothers, who made Flight of the Lost Balloon (1961) directed by Nathan Juran. Though Verne's novel was in the public domain, Fox and Allen brought legal pressure against the Woolners to drop all mention of Jules Verne from their film. The Woolner’s were also stopped from using another title for the film - Cleopatra and the Cyclops, intended to exploit the hype of Fox’s own Cleopatra (1963). Allen's film is played much more for comedy than Juran's film. In Verne's novel and the Woolner Brothers' film, the balloon was named the Victoria. Allen's film renames it the Jupiter with Allen giving the name Jupiter II to the spaceship on Lost in Space. Filming took place in early 1962. It was the only film being made on the Fox lot at the time, due to costs incurred by Cleopatra (1963). The film was entirely shot in Hollywood except for some second unit shots in Africa. Allen wanted to make the film as a straight adventure movie with accent on comedy and youthful romance. He did this to attract teenage girls and mature women who might not normally go