In what ways did journey to the center of the earth show that Jules Verne has some understanding of the earth layers

In his text Jules Verne had somehow drawn an representation of earth's various layers, like an internal hot layer just from approximation. So, one can imply that he had some understanding of earth layers.

Explanation:

During the time that "Journey to the center of the earth" was written the various layers of earth were not discovered. Jules Verne in his science fiction mentioned the various layers, which were not exactly accurate but it showed that he was curious about how earth was made. He speculated an internal hot layer just on the fact that volcanoes spew out magma.