Power Figure (Nkisi N'Kondi: Mangaaka), 19th century, inventoried 1906. Kongo peoples, Yombe group. Chiloango River region, Democratic Republic of the Congo, Republic of the Congo, or Cabinda, Angola. Wood, iron, resin, cowrie shell, animal hide and hair (monkey?), ceramic, plant fiber, textile, pigment; H. 44 1⁄8 in. (112 cm), W. 18 7⁄8 in. (48 cm), D. 14 1⁄8 in. (36 cm). MIBACT—Polo Museale del Lazio, Museo Preistorico Etnografico Luigi Pigorini, Rome
The exhibition Kongo: Power and Majesty (on view through January 3, 2016) culminates with an astonishing display of fifteen N'kisi Nkondi Mangaaka power figures—the result of an eight-year research project that began with the Metropolitan's acquisition of its own example in 2008. On permanent display at the entrance to the Michael C. Rockefeller Wing, this work is presented for the first time with fourteen of the greatest examples drawn from international collections in Berlin, Leipzig, Liverpool, Mainz, Manchester, Paris, Rome, Rotterdam, Stuttgart, Tervuren (Belgium), and Zug (Switzerland), as well as American institutions in Dallas and Detroit.
The majority of these works have rarely, if ever, traveled from their home institution or collection. One of the masterpieces, previously little known beyond academic circles, housed in the Museo Preistorico Etnografico "Luigi Pigorini" in Rome, is no exception. It was originally collected by Carmelo Scardino, an Italian infantry captain in the Congo Free State's Force Publique, or militia, between 1903 and 1906; he later donated it to the Jesuit Museum of the Collegio Romano in 1906. Transferred to the Pigorini that same year, this figure has only left Rome once since—escorted by a motorcade at twenty miles per hour to take part in a 1989 exhibition at the Forte di Belvedere in Florence. Its arrival in New York is the result of long-term collaboration between the Metropolitan and the Pigorini, bringing together a diverse group of conservation, scientifc, technical, and curatorial staff, whose combined efforts have made its long-distance transportation possible.
We spoke with Marco Leona, David H. Koch Scientist in Charge of the Department of Scientific Research; Christine Giuntini, conservator in the Department of the Arts of Africa, Oceania and the Americas; and Ron Street, senior manager of 3D image, molding, and prototyping in the Merchandise and Retail Department, about the multi-year process that prepared the Pigorini's Mangaaka for its unprecedented journey to the Metropolitan.
Helina Gebremedhen: What specific concerns did you have about this work traveling?
Marco Leona: The Pigorini Mangaaka is not only one of the most sculpturally impressive figures [in the corpus] but one of the best preserved, with many of its original surface element additions intact—including the stomach pack, pigments, and large sections of the beard and skirt. Unfortunately, it has suffered some damage—termites created deep tunnels in the legs and ankles, making it vulnerable to further deterioration if it were to be transported upright. Given these issues, the loan was actually initially refused on conservation grounds. It was, however, selected for a full on-site scientific analysis as part of the wider research project into the corpus of Mangaaka power figures.
Christine Giuntini: We were also concerned about the condition of the skirt. The raffia fibers dry out as they age; the fiber bundles used on the outer skirts of the Mangaaka —unlike those in the woven cloths in the exhibition—are very minimally processed, meaning that they're very dry and can break if they shake or if they're touched or moved. We knew that some fibers were already loose, and were embedded within the matrix of the raffia bundles, but travel and movement loosens them and can cause them to come apart.
Detail of the figure's skirt
Fissures in the wood of the legs and ankles caused by insects. Image courtesy of Ron Street and the Department of Physics, University of Bologna
Helina Gebremedhen: How did your respective departments get involved?
Marco Leona: My department [the Department of Scientific Research] got involved because of the opportunity to analyze these objects and do a study, in cooperation with Conservator Ellen Howe, on what resins and other materials were present. Whenever you have a possibility to compare a larger corpus of objects, it's always very valuable to activate ourselves—we can make comparisons, we can make broader range studies.
We worked with physicists from the University of Bologna to set up a portable CT scanner in the galleries of the Pigorini in early 2014—one of the first times this technology was applied to art. Analyses included chemical testing of microscopic wood and fabric samples to glean more information about materials and composition, and CT scans and X-rays to determine the original structure and current condition of the work.
Christine Giuntini: Through my work as a conservator, I have a good amount of experience shipping and packing fragile objects—I make a lot of mounts, and inner supports for mounts—and so I became involved in this project to ship the Pigorini figure. What I normally do is make a cavity [in a foam-like material] that is custom-fit to the object—but that was impossible in this case, as the object was in Italy. The hope, therefore, was that the new data could also be used to find a novel solution to counteract the risks of transportation.
The Mangaaka figure being prepared for scanning at the Museo Pigorini. Image courtesy of the Museu Nazionale Preistorico Etnografico "Luigi Pigorini"
Helina Gebremedhen: In humans, CT scans and X-rays can reveal diseases and broken bones. What can they reveal in a sculpture?
Marco Leona: The CT scans can reveal fascinating new details about the structure and design that are otherwise invisible to the naked eye. For example, we can now clearly attribute the robustness of the beard to the double row of metal blades deeply embedded into the wood, forming its structure, and whose exact arrangement is visible only on these scans.
Top: Computer-generated image showing all the metal objects present in the head. Image courtesy of Ron Street. Bottom left: CT scan revealing exact placing of the structural nails. Image courtesy of Ron Street and the Department of Physics, University of Bologna. Bottom right: Driven into the wood of the sculpture, these blades were then coated with a compound of resin, clay, and animal hair and skin.
Helina Gebremedhen: Did the scans reveal anything unexpected?
Marco Leona: We also discovered that the Mangaaka's ceramic eyes are not inlaid directly into the wood, but instead cover carved cavities where small metal objects have been hidden.
Left: Hidden cavities behind the eyes and the metal objects placed within, visible only on a CT scan. Image courtesy of Ron Street and the Department of Physics, University of Bologna. Right: Detail of the head of the Mangaaka
One particularly striking scan picked up the individual tree rings in the wood. This is a very clear indication that the statue is built out of one single block of wood. With this type of analysis, you can follow the rings, the continuity of the wood through each arm and the torso. You can see the cracks, splits that develop with the natural aging process of the statue.
Tree rings visible on a CT cross-section. Note also the perfectly embedded cowrie shell and "power packet" containing sacred material (bilongo). Image courtesy of Ron Street and the Department of Physics, University of Bologna
The same scan tells us a lot about the engineering of the figure: you sort of expect a statue with a flat belly, like a person, and then they make a hole inside to put the material and around it they add these resins. The scans, however, confirmed that the raised cavity behind the cowrie shell was an integral and original component of the statue and carved as such, with jutting edges that completely contain the sacred matter.
Left: Full-body CT scan of the Mangaaka. Contrast in colors is due to the varying densities of the materials. Right: Detail of the stomach area, showing sacred matter, or bilongo, composed of resin, plant matter, and cowrie shell. Only with the addition of this material would the power of a Mangaaka be activated. Images courtesy of Ron Street and the Department of Physics, University of Bologna
Once the analysis was completed, conservation and technical teams used the new research to design a custom-made mold that could transport the Mangaaka horizontally, on its back, distributing the weight onto its structurally sound hips and shoulders, and off of the fragile legs. This ambitious, high-tech solution addressed both conservation concerns and protected against the stresses of travel, and was key to securing the loan.
First, data from the CT scans was sent to Ron Street, who converted it into a 3D model. A pioneer in the field, Street first began working with 3D imaging in 1999 and specializes in creating facsimiles and high-quality models for museums.
Helina Gebremedhen: What challenges did you encounter in the process of converting a CT scan—a two-dimensional image—into a physical object that can protect a work of art while it is transported in a plane's cargo hold?
Marco Leona: It was great that we had Ron on staff at the Met. It is only through his expertise and experience in 3D modeling and 3D prototyping solutions that we could go from CT scans to this. There are things that aren't visible—something made out of steel, wood, fibers, or fabric is virtually impossible to get a scan of—which means that you have to [manually] fill in a lot of things that are not in here.
Ron Street: Absolutely. You lose a lot of detail in scanning, in printing—all of which has to be re-added by hand if you want it to be as accurate as possible. And when you try to convert different textures into a surface model, the data becomes scattered—it's very work intensive to undo that.
3D surface model of the Mangaaka. The different densities of the materials caused a scattering of the data, which means many objects don't appear as a single protruding form but a long plane across the surface. Image courtesy of Ron Street
Helina Gebremedhen: How was the mold designed, exactly?
Ron Street: Well, once we had our 3D model, we used specialized software and a process called a "Boolean extraction" to essentially carve away sections of a basic rectangular block until the 3D sculpture could fit comfortably within it.
Christine Giuntini: As mentioned, textiles and fibers don't come up on the CT scan, and so when creating the 3D design, the scans couldn't account for the volume of the skirt. Instead, we decided to carve out a cavity, a big void that ran right through the back of the mold. This way, the fragile skirt wouldn't have to be removed prior to packing simply to avoid its being crushed between the figure and the sides of the cavity. We also factored in extra space around protruding features like the arms, ears, and feet, and also added a quarter of an inch of space around the entire Mangaaka to make room for a cushioned Volara® lining.
Early stage of the design process. Only preliminary cuts had been made to the mold, here shown in blue. Image courtesy of Ron Street
Later version of the mold design. Note the large cuts made to accommodate the skirt, feet, and head. Image courtesy of Ron Street
After several rounds of editing, the 3D, computerized designs were sent to a milling company, where a five-axis robotic machine meticulously carved out the mold from a block of high-density urethane foam.
Final designs for the Mangaaka mold. Images courtesy of Ron Street
Conservators and technicians at the Museo Pigorini prepare the crate for shipment. Photograph by James Green
Helina Gebremedhen: What other precautions did you take to transport the Mangaaka safely?
Christine Giuntini: We were still worried about the textile skirt—if it were going to be lying flat, it would still move around a lot with shipping. So I made a sort of "spa robe" for it, with a silk inner lining that would be soft and flexible enough to line the actual figure, and cotton on the outside to provide more body and hold all the raffia and cotton belts and pieces in place.
The unpacking of the Pigorini Mangaaka upon arrival at the Metropolitan. Photographs by James Green
Helina Gebremedhen: Completed in June 2015, the concept and creation of this mold was the result of a unique international and interdisciplinary collaboration. What was it like coordinating this project across two countries?
Christine Giuntini: It was a lot of emails! It was fun. The staff at the Pigorini were great; they were always so helpful and encouraging of everything we wanted to do. It's hard to say; it's totally a team effort. There are a lot of details to consider, and new ideas come from the experience of different departments. It's interdisciplinary. We got to hear a lot of other points of view and work with amazing people.
Marco Leona: Everybody subscribed wholeheartedly to the research project—in Italy, at the Met. We were lucky the people in Bologna were available with the technology, we were lucky to have Ron developing these solutions. From one point of view, the payoff is the final exhibition, the catalogue—that's the intellectual project. But there's also a lot of associated material that will be important—even the solutions. Being able to show that you can do CT scans in situ in a museum, and use a solution like ours for shipment—those are impacts on the field.
Left: Charles Dixon, departmental technician in the Department of Islamic Art, at left, and David Rhoads, collection specialist in the Department of the Arts of Africa, Oceania, and the Americas, at right, carefully place the Mangaaka upright. Right: A last inspection by conservators from the Pigorini before the Mangaaka entered the display case. Photographs by James Green
The application of CT scans and radiography to artwork and use of 3D technology in conjunction with traditional conservation is a pioneering move with the potential to inform and impact conservation, analysis, and shipping practices in the museum sector over the long term. It is a testament to the innovation happening in museums today; the example of the Pigorini Mangaaka could potentially serve as a precedent for other institutions facing similar challenges reconciling travel with the preservation of objects.
Acknowledgments
We would like to thank the following colleagues in Italy for their tireless efforts in making the transportation of the Pigorini Mangaaka to the Metropolitan Museum possible:
Egidio Cossa, Curator, Africa Section, Museo Pigorini
Luciana Rossi, Chemist, Head of the Laboratory of Conservation and Restoration, Museo Pigorini
Maria Francesca Quarato, Restorer-Conservator, Museo Pigorini
Bianca Fossà – Restorer-Conservator, Advanced Institute for Conservation and Restoration, ISCR (Istituto Superiore per la conservazione e il Restauro)
Roberta Bollati, Restorer-Conservator, ISCR
Giulia Galotta, Biologist, ISCR
Maria Rita Giuliani, Biologist, ISCR
Elisabetta Giani, Physicist, ISCR
Dr. Maria Pia Morigi, Physicist, University of Bologna
Prof. Franco Casali, Dept. of Physics, University of Bologna
Dr. Matteo Bettuzzi, Dept. of Physics, University of Bologna
Dr. Eva Peccenini, Dept. of Physics, University of Bologna
Special thanks also to Ellen Howe, conservator in the Department of Objects Conservation, and Adrianna Rizzo, associate research scientist in the Department of Scientific Research.