What role does Hans play in Verne's narrative?
On the one hand, Hans is clearly not as important to the story as Lidenbrock and Axel. He's only invested in this quest because Lidenbrock is paying him and because he has a strong sense of fidelity to his employer. He is not in charge of dictating the overall plan of action, does not critique or oppose, and no doubt does not have the intellectual capacity or knowledge base to understand the things that Axel and Lidenbrock are studying. However, without Hans, Lidenbrock and Axel would be lost. His practical knowledge, his physical and moral strength, his keen senses, and his unflagging commitment to the journey allow the others to make it as far as they do. His characteristics are of the sort needed on a journey that pits man against Nature, for Lidenbrock's at times brash confidence and Axel's trepidation do little to help them when water is scarce, storms are fierce, or climbs are treacherous.
Does it matter that the travelers did not reach the center of the Earth?
One of the great ironies of the text is that the travelers do not actually make it to the center of the Earth. They expend a great deal of physical, emotional, and mental effort to do so but, in the end, the decision to blow up the obstacle in their way means that they are sent rushing back to the surface without ever having reached the point that Saknussemm apparently reached. In one respect, this is a failure; they did not complete their quest. In another, the things they did complete are magnificent; the knowledge they return with is utterly revolutionary. They have changed many scientific disciplines forever, and this is no failure. For Verne the journey is literally as important as the destination.
What is Verne's worldview, as manifested in the text?
It is easy to read Journey to the Center of the Earth as a celebration of science, exploration, and discovery. After all, Lidenbrock is rewarded with academic recognition (and with the satisfaction of having seen remarkable sights) once his journey is over. However, other approaches to the view of science that Verne's text presents are possible. This novel, which features protagonists who run into dilemma after dilemma and famously do not reach their goal, may be meant to indicate that scientific knowledge proceeds along unexpected routes, through error and indirection. Moreover, by making it so that the explorers never reach the center of the Earth, Verne may be signaling that there are some aspects of the world that even science cannot "reach" and explain.
What does Axel's narration bring to the text?
Verne's narrative choice is a fascinating one. He has Axel narrate the story of the journey and includes some of Axel's own writing within the narrative. This approach accomplishes several goals. First, it alleviates any real fear on the reader's part that the travelers (or at least Axel) will not return. It to some extent blunts the impact that Axel's worries and terrified pronouncements of imminent death have on the reader. This fact may allow the reader to focus less on whether or not the travelers will survive, and instead on the awesome things they discover in the bowels of the Earth. Second, it renders the text more complex and its veracity a product of Axel's complicated perceptions. We do not know when he is writing, and the dark in the caverns would sometimes make it impossible for him to actually write in real time. We do not know if anything has been embellished, or even if there was an interim between the journey and the final account. Narrative elusiveness of this sort makes Verne's work strikingly modern.
How does Verne depict the Earth in an anthropomorphic fashion?
One of the ways that the novel attains narrative drive and power is through Verne's manner of describing the Earth into which the travelers descend. This is no cold, barren wasteland. Instead, it is an electric environment charged with an almost sexual energy. Critic William Butcher writes, "the Earth itself is a blatant sexual object, with a rich vocabulary to describe the twin firm white peaks, pointed wave seething with fire, mouths wide open, gaping orifices, cavities, bays, fjords, gashes, and slits; but also the thrusting (and blocking) of the most varied penetrations, glows, eruptions, effusions, and discharges, as well as repeated instances of falling and sinking." He adds that the Earth also seems to have bodily functions such as trembling, sweating, eating, excreting, and birth. Through this sexualized depiction of the subterranean world, we see the fusion of the libido, dreams, and the natural world.