In this early work we see the ingredients of Verne's later _Voyages Extraordinaires_; characters brought or thrown together on a journey to afar; introduction of new characters part way through the story; careful scientific explanation of critical events (the ascension, filling the balloon, rising and falling, ballast); use of dialogue to convey scientific information (the history of ballooning); use of scientific instruments (barometer, compass); chapter heads to presage the story; escapes from perilous events caused by scientific or natural catastrophes.
One may also wonder why Hetzel removed the description of the inflation of the balloon with hydrogen gas. In fact hydrogen is barely mentioned in the revised story. Could it be that while Hetzel approved of Verne's scientific descriptio
