An industrial chemist, graduate of Haverford College, and later attached to the Academy of Natural Sciences. In 1929 he visited southern France and became much interested in cave drawings of early man in the Lescaux caves at Les Eyzies, Dordogne. This increased his interest and work in earth history. Many years were devoted to constructing the Geologic Clock and at one time the original was kept in the Academy's library for safekeeping, but is now in the possession of his nephew in Westtown, Pa. It was in the form of a long scroll, very cumbersome and hard to use. In 1949, he had photostats prepared of the 18 sheets, the positive copy of which was hand colored and with the negative given to the Academy's library.