I.

BELOW THE SURFACE.

DIFFUSION OF KNOWLEDGE.—WHAT THE WORLD BELIEVES.—MUNGO PARK IN AFRICA.—WHY THE NATIVES PITIED HIM.—EXTENT OF UNDERGROUND LIFE.—DISTRIBUTION OF THE EARTH’S WEALTH.—VALUE OF MINES.—THEIR EXTENT AND IMPORTANCE.—COAL AND IRON.—MYSTERIES OF MINES.—EXPERIENCE WITH A NOVICE.—CHANGES OF SEASONS TO A MINER.—DANGERS IN MINES.—LIFE IN CAVERNS.—UNDERGROUND IN METAPHOR.—SOCIAL MINING.—OBJECT OF THIS VOLUME. Page 27