What inspired Jules Verne to write the novel journey to the centre of the earth?

I can"t say this for a certain fact, but in the nineteenth century there was a huge popular interest in Archaeology and particularily ancient writings. The Rosetta Stone was decoded by Champollion early in the century. It was discovered during the Napoleonic wars in North Africa. By Mid century we have the Gold Plates of the Mormons, so it was a popular concept- Verne decided to mix ins some fiction and intrigue. by the way the explorers wind up in Italy and Verne gives the correct compass course- 42 degrees. 42 Degrees II minutes is the trajectory shot taken in mid-ocean from the Catwalk. look at a map.