Verne was happy to take Hetzel's advice. He put a little comedy into his plots, changed his endings to make them happier, and left out a lot of politics that offended previous editors.
Jules Verne wrote adventure stories filled with technological marvels. By contrast, Wells focused on how the future would affect mankind. He foresaw how the world of the 20th century would change society. He worried about overcrowding and pollution, and he felt uneasy about the rapid rise of technology and scientific knowledge.