Thanks to
lehcyfer for pointing me to this post. He provided a link above to my pages on the cigar ships.
cjwalas is correct about Verne's many sources for the
Nautilus, although I think there can be no doubt that the text reference quoted above refers to the
Ross Winans and
Walter S. Winans. These vessels were widely publicized both in English and French publications around the time Verne was writing
20,000 Leagues. Many references associate the cigar ships with submarines although the Winans never considered a submarine and at leat one of their patents specifically excludes them. Some years ago I did extensive analysis of the illustrations and text in
20,000 Leagues to determine Verne's intended shape for the
Nautilus. It's one of my
Nautilus pages here.
Some may be interested in
Oliver Weiss's Ross Winans paper model here. He is planning models of the Baltimore steamer and Walter S as well.
Michael