The egg of Columbus

What was Krahmann’s theory? It was simplicity itself to those who knew the regularity of the Witwatersrand formations. Forty years of mining had proved that the geological strata, despite faults here and there, had been laid down with the precision of a mass-produced layer cake and if there was one thing that was certain in an uncertain world it was that where the Main Reef was found, the shales of the Lower Witwatersrand Series would be found some 400 feet below it.