CHAPTER XXI

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TROGLODYTES OR CAVE-DWELLERS. CANNIBAL CAVES.

Cave Dwellings in the Val d’Ispica—The Sicanians—Cannibal Caves in South Africa—The Rock City of the Themud— Legendary Tale of its Destruction 232

## CHAPTER XXII .

TUNNELS.

Subterranean London—The Mont Cenis Tunnel—Its Length— Ingenious Boring Apparatus—The Grotto of the Pausilippo— The Tomb of Virgil 237

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