News Release

National Park Service and Dartmouth-Hitchcock Use Computed Tomography (CT) Scanning to Solve Art History’s Mysteries

Saint Gaudens Mold CT Scan
CT Scanning reveals the sculptural form inside a 100 year old Saint-Gaudens mold

NPS Photo

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News Release Date: January 31, 2018

Cornish, New Hampshire -- More than a century ago, sculptor Augustus Saint-Gaudens and his assistants used a few dabs of plaster to seal shut roughly two dozen sculpture molds. The molds were then put into storage for safekeeping. Since then, the molds have passed from the Saint-Gaudens family to the non-profit Saint-Gaudens Memorial to the National Park Service, and also survived a catastrophic studio fire in 1944. Through the years, the identities of many of these sealed molds had been lost. Until now.


The National Park Service at Saint-Gaudens National Historic Site and the Department of Diagnostic Radiology at Dartmouth-Hitchcock’s medical center in Lebanon, New Hampshire, have developed a partnership to non-invasively peek at what these molds contain. With computed tomography (CT) scanning, normally used for creating an image of the inside of a patient’s body without surgical intervention, radiologists were able to scan the open interior spaces of these molds and then extrapolate the negative space into a positive digital image of what these molds would have been used to cast. They have also taken the additional step of converting these CT scans into stereolithography which have been used to 3-D print casts of these original Saint-Gaudens works.


The 3-D printed casts of these works will be on display in a gallery exhibit at Dartmouth-Hitchcock until March 2018. The exhibit will be on display in the main entrance rotunda.

“This is an amazing partnership at the intersection of art, science, and history,” said Rick Kendall, superintendent of Saint-Gaudens National Historic Site. “These scans and the resulting 3D prints have literally turned the empty space in these molds into fine works of art that haven’t been seen in a century—something from nothing.”


The molds were revealed to be from sculptural commissions that Saint-Gaudens and his assistants were working to complete close to the end of the sculptors life. The CT scans revealed that the molds included pieces from the following Saint-Gaudens works: Abraham Lincoln: The Head of State (original cast in Chicago, Illinois), the Phillips Brooks Monument (original cast in Boston, Massachusetts), the Sherman Monument, (original cast in New York City, New York), and a bust of politician William C. Whitney. A website showing examples of the scanned objects which allows the public to manipulate these scans in three dimensions can be found at this link:


Perhaps the most interesting piece was a small mold, slightly larger than a football. The scan revealed a very small bust, less than a foot high, of a man with a close-cropped beard; a face that no Saint-Gaudens experts have been able to identify. This small bust is new to art history, not previously part of the Saint-Gaudens sculptural catalog, and may have been a study for a larger piece that was never completed after the artist died in 1907.


Molds are an important part of the process of creating bronze sculpture. Figurative sculptors typically start modeling a sculpture in clay. After undertaking an enlarging process, sculptors typically take a mold of their final version of the piece which captures all of the surface details of their work. The mold is then used to cast the final version in bronze. Today, sculptors use high-temperature rubber for sculpture molds; in Saint-Gaudens’ time, plaster was the medium of choice. The exterior of the plaster molds would be encased in a second, heavier jacket of plaster reinforced with iron called an investment mold. The two sides of the investment mold would fit together like a clam shell to create a full 360-degree mold that would open in order to release the bronze cast. For storage or shipment, these clam shell molds were then often sealed with dabs of plaster to protect the fragile interior details from cracks and abrasions that would impact the final cast.



Dartmouth-Hitchcock is a non-profit, academic health system serving communities in northern New England. The hospital is associated with Dartmouth College and the Audrey and Theodore Geisel School of Medicine and is an active training and research institution. The Dartmouth-Hitchcock campus is located in Lebanon, New Hampshire.


Augustus Saint-Gaudens (1848-1907) was the preeminent American sculptor of the Gilded Age and is perhaps best known for his Civil War era memorials and monuments. His major monuments and smaller works are located in public spaces and art museums around the country and the world. He and his multiple generations of studio assistants who were highly successful in their own right put American sculpture on a global footing. His home, studios, gardens, and personal collection of museum art pieces are now preserved as Saint-Gaudens National Historic Site in Cornish, New Hampshire. For information on seasonal offerings, write: Saint-Gaudens National Historic Site, 139 Saint-Gaudens Road, Cornish, NH 03745; phone: (603) 675-2175; visit the park website and follow the park on Facebook at

Computer Scan of Woman's Head Sculpture
Computer generated image of the form inside a 100 year old sculptural mold created by Augustus Saint-Gaudens and his assistants.

NPS Photo

3D Print of Woman's Head
Once the CT scan of the molds were complete, and a computer image generated, the result could be 3D printed.

NPS Photo

Last updated: January 31, 2018

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