Verne took the name "Nautilus" from one of the earliest successful submarines, built in 1800 by Robert Fulton, who also invented the first commercially successful steamboat. Fulton named his submarine after a marine mollusk, the chambered nautilus. As noted above, Verne also studied a model of the newly developed French Navy submarine "Plongeur" at the 1867 Exposition Universelle, which guided him in his development of the novel's "Nautilus".