A Journey into the Interior of the Earth | Jules Verne | Chapter 25

In a cavern more than a hundred miles below the Earth's surface, alone, bleeding, and convinced he is dying, the narrator Harry hears something impossible: human voices. He is so weak he can barely move, and he has already resigned himself to annihilation. But the sound—a prolonged rumble like thunder followed by what seem to be distant, incoherent words—pulls him back from the edge of unconsciousness. The first word he makes out is "Forladt," repeated several times in a tone of anguish. It is a Danish word, and it belongs to his uncle, Professor Lidenbrock, or their guide, Hans. Harry is not alone after all.

The Acoustic Mystery of the Whispering Gallery

The central puzzle of this chapter is how two people separated by miles of solid rock can hear each other at all. Harry initially fears the voices are a hallucination or an echo of his own cries. But as he drags himself along the cavern wall, he discovers a specific point where the sound reaches its maximum intensity. He realizes the voices are not traveling through the solid granite—which would be impossible—but along the gallery itself. The tunnel possesses peculiar acoustic properties, acting like a wire that carries the electric fluid of sound from point to point. Harry recalls natural phenomena he has read about: the interior gallery of St. Paul's Cathedral and the ancient caverns of Sicily, including the famous "Ea