A Journey into the Interior of the Earth | Jules Verne | Chapter 22

On a Sunday morning deep beneath the earth's surface, the narrator Axel finds himself becoming strangely accustomed to a world without sun, moon, or stars. The party has reached a vast granite grotto where a stream flows so far from its fiery source that the water is now barely lukewarm. But the calm of this rest day is soon broken by a clash between two competing ways of understanding the world: the professor's confident calculations and Axel's anxious arithmetic, each pointing to radically different conclusions about what lies ahead.

The Dispute Over Depth and Distance

Professor Lidenbrock begins the day by taking careful compass readings and reviewing his notes, determined to map their journey as a kind of vertical cross-section of the globe. He announces that they have traveled two hundred and fifty miles from their starting point at Sneffels, placing them directly beneath the Atlantic Ocean. More striking, he calculates they have descended sixteen leagues—roughly fifty miles. Axel immediately objects that this figure represents the maximum thickness science allows for the earth's crust. The professor calmly agrees, then points to the thermometer: twenty-seven and six-tenths degrees. By conventional theories of heat increase with depth, the temperature should be around 1,500 degrees Réaumur. The granite around them should be molten. Instead, it is solid and cool.