But that which formed steps under our feet became stalactites overhead. The lava, which was porous in many places, had formed a surface covered with small rounded blisters; crystals of opaque quartz, set with limpid tears of glass, and hanging like clustered chandeliers from the vaulted roof, seemed as it were to kindle and form a sudden illumination as we passed on our way. It seemed as if the genii of the depths were lighting up their palace to receive their terrestrial guests.

“It is magnificent!” I cried spontaneously. “My uncle, what a sight! Don’t you admire those blending hues of lava, passing from reddish brown to bright yellow by imperceptible shades? And these crystals are just like globes of light.”

“Aye, you think so, do you, Axel, my boy? Well, you will see greater splendours than these, I hope. Now let us march: march!”