Discoveries which almost conclusively prove that the race which inhabited this mysterious cavern, hewn in solid rock by human hands, was of oriental origin, possibly from Egypt, tracing back to Ramses. If their theories are borne out by the translation of the tablets engraved with hieroglyphics, the mystery of the prehistoric peoples of North America, their ancient arts, who they were and whence they came, will be solved. Egypt and the Nile, and Arizona and the Colorado will be linked by a historical chain running back to ages which staggers the wildest fancy of the fictionist.