Twenty Thousand Leagues Under the Sea as an inhabitant of British Colonial India, "is an inhabitant of an oppressed country". Verne took the name "Nautilus" from one of the earliest successful submarines, built in 1800 by Robert Fulton, who later invented the first commercially successful steamboat. Fulton's submarine was named after the paper nautilus because it had a sail. Three years before writing his novel, Jules Verne also studied a model of the newly developed French Navy submarine "Plongeur" at the 1867 Exposition Universelle, which inspired him for his definition of the "Nautilus". The breathing apparatus used by "Nautilus" divers is depicted as an untethered version
Twenty Thousand Leagues Under the Sea crew member who died when an accident occurred under mysterious conditions inside the "Nautilus". When the "Nautilus" returns to the Atlantic Ocean, a pack of "poulpes" (usually translated as a giant squid, although in French "poulpe" means "octopus") attacks the vessel and kills a crew member. Throughout the story Captain Nemo is suggested to have exiled himself from the world after an encounter with the forces that occupied his country that had devastating effects on his family. Not long after the incident of the poulpes, Nemo suddenly changes his behavior toward Aronnax, avoiding him. Aronnax no longer feels the same