Architectural historian of ancient civilizations and engineer; Professor at the Polytechnique (Paris). Choisy was the son of an architect. He studied at the École Polytechnique, Paris, from 1861 to 1863 and from 1863 at the École des Ponts et Chaussées, also in Paris. As part of his education, he traveled to Rome and Athens, beginning in 1866 to study classical architectural elements as many students did. His interest was far more sustained by the structure of these ancient monuments than their decorative detail.

Princeton professor of civil engineering who researched Chartres and other medieval structures on a technical level. Mark was the son of Herman Mark and Laura Bloom (Mark). His father was an attorney. Mark graduated from the City College (modern City College of New York, CUNY) with a BCE in 1952. That same year he was hired at Combustion Engineering, Inc., New York, NY, as stress analyst. He married Janet Harvery (d. 1976) in 1955. In 1957 he joined Princeton University as a research engineer and lecturer.