ON CAVES IN GENERAL.
Their various Forms—Natural Tunnels—The Ventanillas of
Gualgayoc—Eimeo—Torgatten—Hole in the Mürtschenstock—The
Trebich Cave—Grotto of Antiparos—Vast Dimensions of the
Cave of Adelsberg and of the Mammoth Cave—Discovery of
Baumann’s Cave—Limestone Caves—Causes of their
Excavation—Stalactites and Stalagmites—Their Origin—
Variety of Forms—Marine Caves—Shetland—Fingal’s Cave—The
Azure Cave—Cave under Bonifacio—Grotta di Nettuno, near
Syracuse—The Bufador of Papa Luna—Volcanic Caves—The
Fossa della Palomba—Caves of San Miguel—The Surtshellir 133