For five years from 1951 to 1956 he was a petroleum geologist (Senior Geologist) for Esso in Peru before becoming assistant professor in 1956 and professor in 1963 at Princeton University.
Er war fünf Jahre, von 1951 bis 1956, als Erdölgeologe (Senior Geologist) für Esso in Peru, bevor er 1956 Assistant Professor und 1963 Professor an der Princeton University wurde.