Classes might be over for another semester, but for those craving continuing education in art, science, anthropology or ethnomusicology, an exhibition on view through June 16 at the UI's Krannert Art Museum should satisfy just about any hungry intellect. It also will appeal to folks who just love a good mystery.
By Melissa Mitchell
The centerpiece of "Birds on a Drum: Conservation of a Pre-Columbian Musical Instrument" is a 1,500-year-old ceramic drum, believed to be used in conjunction with funerary rituals by the Nasca People, who lived along the southern coast of Peru between A.D. 1 to 700. The exhibition includes extensive wall texts and video information documenting the history of the drum and its recent conservation, as well as a display of tools and materials used in the conservation, other Nasca artifacts from the museum's collection and general information about the Nasca culture.
A treasured piece in the museum's pre-Columbian collection for about 30 years, the ancient instrument is currently in the spotlight because of the amazing secret that lingered undetected all those years just below its surface.
The tale of the Nasca drum has all the elements of a good whodunit -- mystery, suspense, mistaken identity. Except, in the end, the chief "detective" and other investigators involved in solving the mystery were less concerned with who done it than they were with how to undo it.
The story really began back in 1992 when the museum's curatorial staff first noticed that the surface of the drum -- a polychrome slip decorated with three concentric bands of black birds with red-brown beaks on a white background -- was beginning to flake off onto the pedestal on which it was displayed. A local conservator, Sharon Koehler, was called in to evaluate the situation and assist in making a determination of what should be done to conserve the drum.
"My initial inspection of the ancient vessel included a visual examination of its surface using raking light, long-wave ultraviolet light and low magnification," Koehler said. "Interestingly, there were no signs of inclusion scars, burnishing lines or firing flashes, which would normally be associated with the use of local clays, hand-finishing tools and outdoor pit-firing methods. The white ground also appeared mottled and extremely discolored when compared to similarly painted Nasca artifacts."
Given all of this, Koehler strongly suspected that the drum had been subjected to an earlier restoration at some point. Another "big flag" was that the entire decorated surface fluoresced orange under the ultraviolet light. The orange color was characteristic of the presence of shellac.
"Shellac was commonly used in old repairs as both an adhesive and final varnishing layer over painted restorations," Koehler said.
After further examinations, Koehler uncovered additional clues that led her to believe that the drum's entire surface had been significantly altered. For instance, the interior walls of the drum had a uniformity that made it appear unflawed.
But before she could proceed with an appropriate plan for conservation, further examinations and testing had to be completed. So, museum curator Eunice Dauterman Maguire sought and received a grant from the National Endowment for the Arts to fund the laborious conservation work.
In addition to hiring Koehler to do the actual conservation of the drum, Dauterman sought assistance from Sarah Wisseman, director of the UI's Program on Ancient Technologies and Archaeological Materials. According to Wisseman, ATAM's mission is "to link humanities and the sciences, and to provide contacts for analysis" of materials. Over the years, ATAM has assisted with the conservation of other objects in Krannert Art Museum's collection and in the collection of the UI's World Heritage Museum.
In the case of the Nasca drum, Wisseman enlisted the support of technical consultants from various corners of campus -- from the College of Veterinary Medicine to the departments of geology and physics. These consultants then subjected the drum to a variety of tests. Geology professor Steven Altaner and graduate student Robert Ylangan performed compositional analyses using X-ray diffraction and scanning electron microscopy. Under the direction of physics professors Enrico Gratton and William Mantulin in the Laboratory for Fluorescence Dynamics, graduate student Todd French and Peter So, postdoctoral research associate, tested another Nasca artifact in Krannert's collection to explore the idea of using fluorescence spectroscopy to analyze the surface layers of the drum.
The most revealing analysis, however, resulted from simple X-ray radiography, performed by Richard Keen, an animal-imaging technologist at veterinary medicine. Keen also performed computerized axial tomography, or a CAT scan, on the drum, but the X-rays provided the most significant clues to the drum's previous restoration history.
The X-rays "gave us a map of the internal structure of the drum and allowed us to see previously mended joins," Koehler said. "The X-rays also revealed that the drum was severely broken and had been reassembled. The joins and trails of adhesive were readily visible."
One of the biggest surprises the X-rays yielded, however, was the presence of "an ordinary metal carpet tack," which Koehler said was "lodged within a fragment that appeared to be fired earthenware."
Using a needle tool, Koehler explored the surface under the flaking decorations. "In one location, the surface was unusually soft and the needle tool easily loosened surface particles. I was astonished to see a second surface approximately one-quarter of an inch below the first. It was marked with a black shape that resembled the tip of a bird wing from the exterior decoration."
After conducting solubility tests, the conservator removed some of the surface material. That was all it took to at last confirm her mounting suspicions: "The entire original surface of the drum was concealed under layer of shellac, overpaint and tinted plaster."
Koehler said that although "it's not unusual to find extensive restorations of antiquities," never before had she seen anything like what had been done to the drum. In an effort to make it cosmetically pleasing, the previous conservator had constructed a whole new drum around the original object, in effect, turning it into a replica of itself. The conservator even attempted to recreate the original bird design on the surface.
Although such a restoration would be considered blasphemous, and certainly unethical by today's standards, Koehler said work done to the Nasca drum is merely indicative of how much the conservation field has evolved over the past 50 years. When the drum originally was restored, she said, conservators were more concerned with aesthetics -- making the object look good. And, often -- as was the case with the Nasca drum, which was deteriorating -- the practices used to achieve the desired aesthetic turned out to be harmful or destructive.
"Conservation today is more concerned with presenting objects to the public in an honest fashion," Koehler said.
To properly conserve the Nasca drum using today's accepted standards, she first had to disassemble it, remove the destabilizing shellac, adhesive and fill material, then reassemble it using adhesives and infill materials considered to be "reversible."
Although Koehler was primarily responsible for the actual restoration work, decisions about how to proceed at various stages of the restoration were made collaboratively by the project team, which included anthropology professor Helaine Silverman and coordinating curator Rachael Freyman.
"Our aim was to bring the drum back to an exhibitable condition while remaining thoroughly sympathetic to the original," she said. Being an educational institution, the museum was committed to displaying the drum with its original surface exhibiting signs of age and weathering. The surface scratches and losses in the polychrome slip were allowed to remain as the original decoration is sufficiently complete."
Even though some people may be disappointed by modern conservation techniques because the restored objects don't appear to be perfect, Koehler said she thinks the museum-going public is gradually learning to appreciate restorations that preserve the integrity of the artifacts.
In the case of the current exhibition at the UI museum, Koehler said viewers are also reminded always to remember that "what we look at is not always what it seems."
Also on view at Krannert Art Museum through June 16 is an exhibition that highlights the conservation of another work of art in the UI's collection. "Girl With the Scarf: Conservation of a Sculpture at Allerton Park" documents Koehler's restoration of a sculpture by Lili Auer. The focal point of the exhibition, which is on view near the entrance to the museum's Kinkead Pavilion, is the restored statue. More information about that project appeared in the April 6, 1995, issue of Inside Illinois. The article is accessible through the World Wide Web at gopher://gopher.uiuc.edu:70/77/UI/II/1995/.waisindex/indexg?koehler.