Verne is celebrated as the first great exponent of science-fiction writing. He knew Delibes as a student, and became close friends with both the younger Dumas (they collaborated on two plays) and his father, who helped him professionally. Verne’s publisher Hetzel introduced him to Nadar — another great friend, with a shared interest in ballooning (he helped inspire ‘Five Weeks in a Balloon’) and in the bohemian lifestyle. Hugo gave him writing advice, Sand wrote as an enthusiastic fan, and Roussel paid him a visit. Although Verne revered François Arago and knew his brother, it is unclear whether any direct contact existed.