On the basement level of the Yale Center for British Art (YCBA), an 18th-century terracotta bust of British poet Alexander Pope (1688–1744) sits atop a large white table as a fine red laser beam moves across its surface. Nearby, imaging specialists and computer scientists— including one on Skype from Italy — huddle around a cluster of laptops, comparing notes on the image that appears on their screens.
At first glance, the terracotta Pope appears to be a lone object waiting for its exam to conclude. In reality, however, the sculpture is one of eight related busts that form part of a large international research project in technical art history that will provide information about 18th-century sculptural techniques to art historians, conservators, and scientists.
In addition to the research project, the busts of Pope, made by Louis-François Roubiliac (1695–1762), will be shown this spring in the YCBA exhibition “Fame and Friendship: Pope, Roubiliac, and the Portrait Bust in Eighteenth-Century Britain,” on view Feb. 20–May 19. The YCBA has also organized a related conference in February and a workshop in May that will be dedicated to research questions raised by the scanning project.
The emerging field of technical art history
“This is one of several technical art history projects at the YCBA that looks at art works in the collection and relates them to other works from museums around the world,” said Martina Droth, head of research and curator of sculpture at the YCBA. “For this project, we are using digital imaging techniques in order to learn more about how sculptures were made before the advent of mechanical reproduction.”
Technical art history is a relatively new but quickly developing field that considers the material history of artifacts in tandem with other art historical questions. This interdisciplinary approach — involving art historians, conservators, and scientists, among others — helps reveal the full story of an object by connecting its production and material construction to its historic and cultural meanings.
For the portrait bust project, the YCBA has brought together a team of art historians, curators, conservators, imaging specialists, computer scientists, and geologists from across the university to work over a period of several months. A true marriage of art and science, the project involves the Yale Graphics Group (YGG) in the Department of Computer Science; the Center for Conservation and Preservation at West Campus; the Yale Digital Collections Center (YDC2), also at West Campus; the Yale Center for British Art; the Yale University Art Gallery; and the Yale Peabody Museum of Natural History, where Stefan Nicolescu, manager of the mineralogy collection, has been attempting to identify the source of the marble used for several of the busts.
The many portraits of Alexander Pope
Given all the artists and subjects available to researchers, the question is: Why Alexander Pope?
Simply put, no contemporary figure in 18th-century Britain was more widely depicted than Pope, says Malcolm Baker, curator of the “Fame and Friendship” exhibition and Distinguished Professor of the History of Art at the University of California, Riverside. According to Baker, Pope took great pains over how he was represented and carefully fashioned his public persona through images.
As the leading literary figure of his age, Pope was sculpted by numerous artists, though none represented the poet so compellingly as Roubiliac, says Baker. As he notes in his upcoming book about the sculptural portrait (“The Marble Index,” Yale University Press), the artist’s sensitive portrayal of leading figures of the British Enlightenment revolutionized the genre and helped make portrait busts one of the principal means of disseminating images and spreading fame in the 18th century.
An 'extraordinary face'
A young Sir Joshua Reynolds (1723–1792) noted that Pope “had an extraordinary face,” with “a pallid, studious look; not merely a sharp, keen countenance, but something grand, like Cicero’s.” Roubiliac’s portrait of Pope emphasized the delicacy and angularity of his face, heightening the viewer’s sense of the poet’s physical fragility (it is believed that Pope suffered from curvature of the spine, possibly caused by Pott’s disease).
In an era of “selfies” and viral images, the idea of sculpture as a means of spreading celebrity might seem odd. Yet, according to Droth, Pope exemplified the phenomenon.
“These portrait busts were commissioned by people who admired Pope, people in his friendship circle, as well as by libraries seeking to represent the great figures of British literature,” said Droth. “Pope was a key figure among the literary canon being shaped during the Enlightenment.”
The focus of the YCBA exhibition “Fame and Friendship” is the series of Pope busts made by Roubiliac from 1738 to 1760. It includes signed and documented versions, as well as a number of adaptations and copies that were modeled after them. In addition to the sculptures, “Fame and Friendship” features paintings, drawings, photographs, and rare books from private lenders and public collections, including the YCBA, the Beinecke Rare Book and Manuscript Library, and the Lewis Walpole Library at Yale.
History of Yale's Pope portrait research
The exhibition builds on work that began nearly half a century ago with W.K. Wimsatt ’39 Ph.D., Sterling Professor of English and Pope’s most renowned iconographer. Wimsatt, who taught at Yale from 1939 to 1975, dedicated nearly 20 years to researching Pope’s portraits. In 1961 he organized an exhibition at the National Portrait Gallery, London, featuring six Pope busts alongside painted portraits of the poet. Four years later he published “The Portraits of Alexander Pope” (Yale University Press). Wimsatt made detailed notes about the images in a scrapbook that is part of a vast archive of his research files now housed in the Beinecke Rare Book and Manuscript Library.
“Many of the faculty at Yale knew Wimsatt, as well as Maynard Mack, who wrote the definitive biography on Pope,” said Droth. “There is a real Yale history to this project.”
The genesis for the exhibition grew out of the technical art history project, which was also Baker’s idea. A few years ago, he noticed a portrait bust of Pope by Roubiliac that appeared on the art market. It was very similar to the one owned by the YCBA, but had disappeared into a private collection for years. It was quickly purchased for the Rothschild Foundation to be reunited with its companion portrait bust of Sir Isaac Newton. The two will be displayed at Waddesdon Manor, the Rothschild House, which is run by the National Trust and the Rothschild Foundation (Waddeson has co-organized the “Fame and Fortune” exhibition, which will travel there following its Yale premiere.)
Initially, the idea was to have the YCBA and Waddeson busts examined together, but it was soon decided that only comparing two marbles wouldn’t reveal much.
“We expanded the idea into a proper project to include the terracotta and plaster models, along with other known portrait busts of Pope,” said Droth. “We started talking with colleagues at the [Yale] art gallery, the Institute for the Preservation of Cultural Heritage, and imaging people, and before long we had a whole group together and started hatching out what could be done and how.”
The exhibition presented Yale with an opportunity to bring all of the Roubiliac busts together with Yale’s state-of-the-art equipment and research facilities. “It was our chance to do a systematic analysis across the board,” said Anne Gunnison, assistant conservator at the Yale University Art Gallery, who is coordinating the digital imaging project.
Details not visible to naked eye
If the terracotta bust on the white tabletop is any indication, scanning a piece of sculpture is no small task. The imaging equipment in use at the YCBA, which was brought over from the YDC2 lab, employs a triangulation method to capture the object. As the laser moves across the surface of the bust, it captures points reflecting the surface geometry. These points are grouped into a “points cloud” for each scan.
“We have to do many, many scans and merge them,” said Ying Yang, a post-doctoral fellow in the computer science department, adding that each set of data must also be cleaned to remove visual “noise,” such as objects in the background or the table. One bust may have to be scanned up to 40 times in order to capture the geometry requisite for a 3D model. These overlapping scans are then cleaned, aligned, merged, and processed into comprehensive 3D models.
According to Yang and his colleagues — Ruggero Pintus, also in the computer science department, and Chelsea Graham of YDC2 — it takes about an hour to calibrate the camera and each scan takes approximately three minutes (at 40 scans per object that can easily add up to hours of data collection). The scans are then assembled into a detailed image. Once constructed, the 3D image allows one to look at an object from any vantage point and zoom in to see tiny details not visible to the naked eye, such as tooling marks, and to discover similarities and difference in surfaces, dimensions, construction, and materials.
“We make assumptions about sculptural production,” said Droth. “For example, we assume that a terracotta version is a model and that the plaster version is cast from it, and then a marble is taken from the plaster.”
But variations in the details of each version have led the researchers to question whether that sequence of events is actually correct. “It’s especially important to establish the relationship between the terracotta and plaster versions, and how each relates to the marble bust,” she said. “It tells you a bigger story about process, which expands the project to have relevance to 18th century sculpture practice.”
Human variation and error
All of the busts in the YCBA’s project were made before the advent of the pointing machine, which came into use in the late 18th century. A pointing machine is not actually a machine, but a tool used by sculptors to transfer measurements accurately from model to marble. As all of the Pope sculptures were made by hand, researchers are looking at how the dimensions vary from version to version.
“We want to see how much human variation and error there is in the carving of busts,” said Droth. “We assume they are the same object, but we don’t really know. We haven’t been able to see them next to each other before. From a photograph they look like they are the same, but these were all carved by hand, so what is the degree of exactitude?”
Gunnison noted that while the portrait busts will share a physical space for a finite period of time, by scanning them, researchers will have a digital repository of information that they can go back to time and again.
“We can overlay and compare the different 3D images of the busts,” she said.
In addition to 3D imaging, all of the busts are also making a trip to the YCBA’s photography studio, which is taking high-resolution images as well as ultraviolet images of each object.
“We will have a baseline of data across the objects,” said Gunnison. “You can look at a 3D model, a UV image, and a hi-res image, and then make comparisons.”
Gunnison and Droth expect the scanning project will take another six months to a year to complete. Approximately five of the eight portrait busts by Roubiliac were captured prior to the exhibition opening, while others will be scanned over the course of the exhibition and possibly beyond.
More technical art history projects underway
In addition to all of the activity surrounding Alexander Pope and Louis-François Roubiliac, the YCBA is working on technical art history projects related to Tudor panel paintings; The Reynolds Research Project, examining works in the Wallace Collection, London, by Sir Joshua Reynolds; and a collaboration with the National Gallery in Washington, D.C., to analyze Benjamin West’s “Battle of La Hogue” (ca. 1778).
Droth is also working on the first wide-ranging exhibition of Victorian sculpture ever undertaken by a museum. Organized in association with Tate Britain, the show will run Sept. 11–Nov. 14 at the YCBA.
As she plans for her next major show, Droth has not lost focus on the project at hand. It might be a few years before the research is completed — and a book about the project is published — but she is pleased with how far they have come.
“It has been a real team effort,” said Droth. “We got everybody together to talk about what we might get out of this project and which elements we could pursue. It has been incredibly rewarding and I look forward to seeing how it moves the field forward.”