The study of medieval churches in Europe was transformed by the work of Robert Mark (1930–2019). He was an engineer who applied techniques of modern structural analysis to the study of Gothic architecture.
Robert was born in the Bronx, New York, and grew up on City Island. Growing up surrounded by the sea, he loved sailing and racing, which led to a home machine shop for making metal boat parts. He credited much of his later success to the practical skills he learned in the process. He attended the Bronx High School of Science and then the City College of New York, earning a degree in civil engineering. His love of constructing things and of engineering more generally was accompanied by a life-long love of the arts—encouraged by his older sister Beverly’s gift of a membership to the Museum of Modern Art (MOMA) when he was in high school. His passion for the arts also embraced classical music and led to his attending a concert where he met his future wife Janet Harvey, a pianist who loved Bach.
Mark participated actively in the remarkable technological flowering seen in the United States after the Second World War, helping to design reactor containment vessels for the earliest nuclear submarines, and performing structural analysis of designs for stellarators, fusion reactor prototypes of a sort first proposed at the Princeton Plasma Physics Laboratory. On the strength of this work, he was hired in 1962 by Princeton University’s Department of Civil Engineering, with which he remained affiliated until his retirement more than three decades later.
Yet Robert did not remain in the silo of civil engineering, fascinated as he was by that field and innovative as his work in it was. Prompted by conversations with students and with colleagues including Columbia University’s Robert Branner, he developed an interest in Gothic cathedrals, whose structural performance he sought to model. In the process, he became a great admirer of E. E. Viollet-le-Duc, who had guided the restoration of many French Gothic structures in the nineteenth century. As architectural historian Carolyn Malone recalled, “it took a broad leap of the imagination and an adventurous spirit to think of using small scale epoxy models of sections of Gothic churches to simulate the forces in the building resulting from the load of their own weight and wind pressure.” (Ethan Mark, “Robert Mark: In Memoriam,” in Robert Bork, ed., The Analysis of Gothic Architecture: Studies in Memory of Robert Mark and Andrew Tallon, 8–11 [Leiden: Brill, 2023], 9.)
Malone was referring to Mark’s main research method from the late 1960s to the 1980—photoelastic stress modeling. This modeling involved shining polarized light through plastic scale models that had been loaded to simulate the loads on the full-scale structure. This approach had the great advantage of yielding information about every point in the modeled structure, and it produced visually compelling images that earned Mark early fame. Skeptics objected that the plastic models were monolithic structures with material properties very different than medieval masonry, but Mark understood his techniques well enough to arrive at important conclusions both about individual cathedrals, and about the developmental history of Gothic architecture, more generally. He called attention, for example, to the highly efficient structure of Bourges Cathedral, with its steeply sloped flying buttresses, and he admired the nave of Amiens Cathedral, whose pinnacles helped to keep the masonry of the culées in a state of compression. (Architectural historians previously had viewed those pinnacles as purely ornamental.) More generally, Mark recognized the importance of experimentation and competition in driving the early development of Gothic architecture, while noting the increasing standardization and codification of building practices in the later Gothic era.
Starting in the 1970s, Mark began to use computers to model historic structures. Using finite element modeling, he showed that quadripartite vaults displaced sexpartite vaults in Gothic construction after 1200 in large part because they exerted less longitudinal thrust in the construction process. Looking further back in time, he also used this technique to investigate the structures of the Pantheon in Rome and Hagia Sophia in Constantinople, demonstrating that their domes behave essentially like a series of arches leaning together, rather than like monolithic “pot lids.”
Mark also increasingly studied post-medieval buildings of various kinds. He explored Saint Paul’s Cathedral in London, calling attention to the contrast between Christopher Wren’s conservative design for its nave and his innovative design for its dome. He also called for a tighter integration between modern architectural design and structural engineering, promoting his views not only in print, but also on television, most notably in the 1988 NOVA special “The Mystery of the Master Builders.” Finally, Mark worked as a consulting engineer for the National Cathedral in Washington DC, continuing in that role for long after his 1996 retirement from Princeton as professor of civil engineering and architecture.
Robert Mark brought an unusual and highly original background to his architectural scholarship, and he also engaged fruitfully with the work of many friends and associates over the course of his long career. In studying Gothic architecture, he drew inspiration from Branner; he collaborated with colleagues including Lon Shelby and Bill Clark; he was a generous co-author who published with many students; and he launched the careers of Robert Bork and Andrew Tallon, both of whom also studied with Stephen Murray. At Princeton, he associated mainly with engineers David Billington and Ahmet Çakmak, and with architectural historians Francois Bucher, Alan Borg, and Slobodan Ćurčić. He held summer seminars to teach architectural historians about structures, which resulted in a book to which they subsequently contributed chapters (Architectural Technology up to the Scientific Revolution, 1993). Through such ties, and through his many publications, Robert Mark contributed significantly to advancing the study of architectural history, and the study of technological history more generally. He was instrumental, not only in developing an original methodology for the study of historical buildings, but in bringing together scholars and professionals in diverse fields to study and discuss historical buildings in new ways. He promoted interdisciplinarity long before the word gained currency in the academy, and thereby promoted fresh ideas across several fields including the history of architecture and the history of technology.
Robert was devoted to his three sons, Christopher, Peter, and Ethan, to their families, including his five grandchildren, and to his long-time companion, Carol Grissom, a conservator at the Smithsonian Institution in Washington, DC. Those of us who were his friends recall delicious dinners, prepared by Carol and Robert, and many stories about his beloved family members. He also brought his professional loves into his family life. For example, he and Carol took a grandchild from time to time to visit Gothic cathedrals in France. He accompanied Carol on her odyssey to see zinc sculptures around the United States for her book on that subject. He was good friends, not only with scholars in the academy, but with the supervising master mason of the Washington Cathedral, Joe Alonso, whose skills he undoubtedly appreciated more than most.
Robert Mark brought together technical methods of modern civil engineering and architectural history. In doing so, he transformed several fields, including the history of technology.
Robert Bork and Pamela O. Long, 2026
Bork, Robert, Robert Mark, and Stephen Murray. “The Openwork Flying Buttresses of Amiens Cathedral: ‘Postmodern Gothic’ and the Limits of Structural Rationalism.” Journal of the Society of Architectural Historians 56 (1997): 478–93.
Mark, Robert. “Architecture and Evolution.” American Scientist 84 (1996): 383–89.
Mark, Robert, ed., Architectural Technology up to the Scientific Revolution: The Art and Structure of Large-Scale Buildings. Cambridge, MA: MIT Press, 1993.
Condit, Carl W. Review of Experiments in Gothic Structure, by Robert Mark. Technology and Culture 24, no. 2 (1983): 261–63. https://muse.jhu.edu/article/891261.
Mark, Robert. Experiments in Gothic Structure. Cambridge, MA, MIT Press, 1982.
Mark, Robert and Ahmet S. Çakmak, eds. Hagia Sophia from the Age of Justinian to the Present. New York: Cambridge University Press, 1992.
Trilling, Leon. Review of Light, Wind, and Structure: The Mystery of the Master Builders, by Robert Mark. Technology and Culture 32, no. 2 (1991): 408–9. https://dx.doi.org/10.1353/tech.1991.0108.
Mark, Robert. Light, Wind, and Structure: Mystery of the Master Builders. Cambridge: MIT Press, 1990.
Mark, Robert, and David P. Billington. “Structural Imperative and the Origin of New Form.” Technology and Culture 30, no. 2 (1989): 300–29. https://dx.doi.org/10.1353/tech.1989.0095.
Bonde, Sheilla, Clark Maines, and Robert Mark. “Archaeology and Engineering: The Foundations of Amiens Cathedral.” Kunstchronik 42 (1989): 341–48.
Huang, Yun Sheng, Robert Mark, and Avery M. Wellman. “Westminster Hall’s Hammer-Beam Roof: A Technological Reconstruction.” APT Bulletin: The Journal of Preservation Technology 20 (1988): 8–16.
Mark, Robert. “Reinterpreting Ancient Roman Structure.” American Scientist 75 (1987): 142–50.
Mark, Robert, and Paul Hutchinson. “On the Structure of the Roman Pantheon.” The Art Bulletin 68 (1986): 24–34.
Mark, Robert, and William W. Clark, “Gothic Structural Experimentation.” Scientific American 251 (1984): 176–85.
Billington, David P., and Robert Mark. “In Response to “Another View of ‘The Cathedral and the Bridge’”.” Technology and Culture 25, no. 3 (1984): 595–601. https://muse.jhu.edu/article/889995.
Clark, William W., and Robert Mark. “The First Flying Buttresses: A New Reconstruction of the Nave of Notre-Dame De Paris.” The Art Bulletin 66 (1984): 47–65.
Billington, David P., and Robert Mark. “The Cathedral and the Bridge: Structure and Symbol.” Technology and Culture 25, no. 1 (1984): 37–52. https://muse.jhu.edu/article/890079.
Taylor, William, and Robert Mark. “The Technology of Transition: Sexpartite to Quadripartite Vaulting in High Gothic Architecture.” The Art Bulletin 64 (1982): 579–87.
Darn, Harold, and Robert Mark. “The Architecture of Christopher Wren.” Scientific American 245 (1981): 160–75.
Shelby, Lon R., and Robert Mark. “Late Gothic structural design in the ‘instructions’ of Lorenz Lechler.” Architectura 9 (1979): 113–31.
Mark, Robert. “Structural Experimentation in Gothic Architecture: Large-scale Experimentation Brought Gothic Cathedrals to a Level of Technical Elegance Unsurpassed until the Last Century.” American Scientist 66 (1978): 542–50.
Mark, Robert, and Robert Willis. “Viollet-le-Duc, and the Structural Approach to Gothic Architecture.” Architectura 7 (1977): 52–64.
Alexander, Kurt D., Robert Mark, and John F. Abel, “The Structural Behavior of Medieval Ribbed Vaulting.” Journal of the Society of Architectural Historians 36 (1977): 241–51.
Wolfe, Maury, and Robert Mark. “The Collapse of the Vaults of Beauvais Cathedral in 1284.” Speculum 51 (1976): 462–76.
Mark, Robert, and Maury Wolfe. “Gothic Cathedral Buttressing: The Experiment at Bourges and Its Influence.” Journal of the Society of Architectural Historians 33 (1974): 17–26.
Mark, Robert, James K. Chiu, and John F. Abel. “Stress Analysis of Historic Structures: Maillart’s Warehouse at Chiasso.” Technology and Culture 15, no. 1 (1974): 49–63. https://muse.jhu.edu/article/892824.
Borg, Alan, and Robert Mark. “Chartres Cathedral: A Reinterpretation of Its Structure.” The Art Bulletin 55 (1973): 367–72.
Mark, Robert, John F. Abel, and Kevin O’Neill. “Photoelastic and Finite-Element Analysis of a Quadripartite Vault.” Experimental Mechanics 13 (1973): 322–29.
Mark, Robert. “The Structural Analysis of Gothic Cathedrals: Chartres vs. Bourges.” Scientific American 227 (1972): 90–101.
Mark, Robert. “Gothic Cathedrals and Structural Rationalism.” in Proceedings of the New York Academy of Sciences 33 (1971): 617–24.
Mark, Robert, and Ronald S. Jonash. “Wind Loading on Gothic Structure.” Journal of the Society of Architectural Historians 29 (1970): 222–30.
Mark, Robert. “Photomechanical Model Analysis of Concrete Structures.” In Models for Concrete Structures. Detroit: American Concrete Institute, 1970, 187–214.
Mark, Robert, and Richard Alan Prentke. “Model Analysis of Gothic Structure.” Journal of the Society of Architectural Historians 27, no. 1 (1968): 44–48.
Mark, Robert. “The Church of St. Ouen, Rouen—A Reexamination of Gothic Structure.” American Scientist 56 (1968): 390–99.
Rausch, Thomas M., and Robert Mark. “Model Study of Buttressing the Piers in Chartres Cathedral.” Gesta 6 (1967): 21–24.