New Isotope Ratio Mass Spectrometry Laboratory provides critical data to identify US Airways bird strike as migratory Canada Geese
The Smithsonian’s Museum Conservation Institute (MCI) scientists, working with researchers at the National Zoological Park (NZP), the National Museum of Natural History (NMNH), the Federal Aviation Administration, and the National Transportation Safety Board, analyzed elemental isotopes from feather remains from the January15, 2009, US Airways Flight 1549 bird strike. The plane took off from New York’s LaGuardia Airport, and then collided with a flock of geese approximately 2,900 feet above the ground. The pilot made an heroic and successful emergency landing in the Hudson River. MCI scientists, using new Thermo Scientific gas isotope ratio mass spectrometers, compared the stable-hydrogen isotopes of the bird-strike feathers to samples from migratory Canada geese and from resident geese close to LaGuardia Airport. Analysis revealed that the isotope values of the geese were most similar to migratory Canada geese from the Labrador region, and were significantly different from those residing year-round near New York City. This knowledge is essential for wildlife professionals to develop policies and techniques that will reduce the risk of future bird-airplane collisions. The team’s manuscript, the first publication from the new mass spectrometry center housed at MCI, was published in the journal Frontiers in Ecology and the Environment. With this auspicious start, the mass spectrometry center will contribute to the growing body of research on topics such as avian migration, wetland ecology, and wildlife dietary history. In addition, the center will develop new applications for stable isotope analysis in conservation and archaeological science as well as provide traditional services to those disciplines already heavily based on stable isotope analysis. In its first year of operations, the center conducted more than 6,000 analyses, with over 2,000 for NZP projects, and over 1,000 each for the Smithsonian Environment Research Center (SERC), NMNH, and MCI projects.
Proteomics identifies the flora and fauna in archaeological and ethnographic objects
The Smithsonian’s Museum Conservation Institute (MCI) is developing proteomics capabilities as a part of the Institution’s central research infrastructure – the Mass Spectrometry Center. Proteomics, the large-scale study of protein structure and function, allows us to gather more information from Smithsonian collections, cultural objects and biological specimens, and to learn more about their materials, their origins, and their deterioration. Already, MCI fellow Caroline Solazzo has conducted pioneering proteomics research to identify traces of Beluga whale blubber on St. Lawrence Island potsherds, sheep’s wool and cow leather objects found with a bronze disk from an 1,800 year old Mongolian burial, and wooly dog’s hair woven into blankets from the Coastal Salish Tribes of the Pacific Northwest collected by the Wilkes expedition (1838-1842). This work, conducted on Smithsonian collections at proteomics facilities in France and England, has produced a number of well-regarded, ground-breaking archaeological publications. Proteomics techniques are one way to move beyond identification of organisms to look at the activity and dynamics of their populations, their use in cultural and artistic expression, and their role in sustainable ecosystems.
The science of conserving ancient Mongolian monoliths
Deer Stones, Mongolia’s mysterious ancient monuments, are the country’s most important archaeological treasures and some of the most spectacular expressions of Bronze Age megalithic art anywhere in the world. These 3,000-year-old carved stone monoliths standing 1 to 4 meters high are scattered in unprotected sites throughout northern Mongolia. Deer Stones bear elaborate depictions of flying ‘spirit deer’ with swept-back antlers and legs folded beneath their bodies—perhaps representing spirits of ancient chiefs and clan leaders. MCI Senior Objects Conservator Rae Beaubien, with the assistance of the Office of Exhibits Central Model Maker Carolyn Thome and fellows and interns, worked with a multidisciplinary Smithsonian team led by William Fitzhugh, NMNH, and Paula DePriest, MCI Deputy Director, to study, protect, and preserve these monuments in their natural settings, and to capture their pictorial information with 3-D laser scanning. This information will be available virtually through the Smithsonian Web to researchers studying the Deer Stone iconography. Our 3-D laser scans serve also as a snapshot of the condition of the stone monuments, with resolution in the millimeter range, pinpointing not only the surface decorations but also the physical evidence of damage. Using GIS techniques, we can wrap a sketch map marked with today’s visible damage – bird droppings, lichens, and surface erosion – like a skin around the 3-D image. Then we can ask if a type of stone damage is correlated with a particular feature – a concave surface, a roughened stone texture, a heavily carved area, a patch of lichen or fungi, etc. Over time we can follow changes in the stone, to see how rapidly the damage increases, and if the organisms come and go either on their own, in concert with climate changes, or after a treatment to control them.
Preserving and conserving our cultural heritage against biological attack
Conservation and preservation of our cultural heritage requires an understanding of the complex chemical, physical, and biological threats to its integrity. Recently, MCI’s Director Robert J. Koestler chaired a panel “Microorganisms in subterranean environments” for the French Ministry of Culture at their International Symposium Lascaux and Preservation Issues in Subterranean Environments, February 26-27, 2009. This meeting was convened to investigate anthropogenic-induced changes over the past decade to one of the greatest cultural treasures of the western world – the Paleolithic painted cave at Lascaux, France. The almost 2,000 vivid and vivacious animal paintings made from luminous iron and manganese oxide, approximately 16,000 years old, are suddenly threatened by the rapid growth of garden-variety soil molds. Some experts proposed that the mold damage was a consequence of global change, although this is still unproven (see Science News, June 6, 2009, p. 12.) On April 20-22, 2009, MCI convened its own international workshop on the topic, Biocolonization of Stone: Control and Preventive Measures, to provide a discussion forum for biologists, material scientists, and conservators with expertise in microbial (bacterial and fungal) damage to stone. The workshop explored new methods to detect and prevent microbial deterioration and colonization, and future directions for collaborative research. The conference papers will be published as a volume in Smithsonian Contributions to Museum Conservation. MCI’s chemical analysis, including fine-scale physical mapping of surface details, developed in our Mongolian Deer Stone project, have shaped our current understanding of Lascaux’s paintings and now this knowledge will help us to mitigate the current environmental and microbiological threats to Lascaux. By combining chemical, physical, and biological approaches and concepts, MCI is better able to preserve cultural heritage for future generations.
Flooded with light - studying the effects of light on museum collections
Light has the potential to cause damage to objects in museum collections. The Smithsonian’s Museum Conservation Institute (MCI) Senior Research Scientist Marion Mecklenburg has worked with the Smithsonian American Art Museum, the National Portrait Gallery, and the Hirshhorn Museum and Sculpture Garden to investigate light levels, especially in recently constructed or renovated exhibits and collection spaces that take full advantage of natural lighting via skylights and windows to enhance the visitor’s experience. Although accommodations and preventive measures have been made for controlling the light intensity and spectrum, especially ultraviolet radiation, visible light levels recorded in some galleries and collection storage exceed accepted museum standards. Are these standards valid? Are collections in danger of fading? MCI researchers are experimentally testing the fading of materials under widely different light intensities. With an understanding of fading and its interaction with temperature, relative humidity, and ambient or reduced oxygen levels, we will develop guidelines for acceptable lighting levels. These guidelines complement our recommendations for safe temperature and relative humidity levels in exhibits and collections.
Portable instruments detect pesticide residues on NMAI and NMNH ethnographic collections
The Smithsonian’s Museum Conservation Institute (MCI), working with an extensive network of Smithsonian collaborators, has addressed pesticide detection and quantification, assessment of health risk, and strategies for mitigating that risk. Pesticides were applied historically to Smithsonian collections to eradicate and/or prevent infestation by insects, rodents, and mold. Many of these chemicals are now known to be hazardous to human health. MCI visiting scientist and fellow, Odile Madden, developed protocols for calibrating and using portable X-ray fluorescence instruments to detect heavy metal pesticide residues — arsenic, lead, and mercury — on ethnographic collections. Currently, she is developing methods to trap and detect volatile organic pesticide residues using Raman spectroscopy. The protocols and results have been reported in a number of high-profile invited presentations and publications. The goal of the collaborative project, with the National Museum of the American Indian and the National Museum of Natural History, is to identify potentially hazardous pesticide residues on collections and, ultimately, to accurately communicate whether or not the risk posed is significant.
Investigating how and when some of the first humans entered North America
For decades scientists have hypothesized that the first inhabitants to enter the New World arrived some 12-15,000 years ago via the Bering Land Bridge. After the fall of the Soviet Union in 1991, researchers from North America and the former Soviet Union joined forces in an attempt to confirm the land bridge hypothesis. It was believed that when scientists from these two continents got together that it would be a simple matter of comparing their respective datasets. Despite all attempts, no one has yet been able to unequivocally demonstrate that a migration from northeast Asia to North America occurred via the Bering Strait 12-15,000 years ago. One approach, focused on the analysis of obsidian, is providing new clues to the peopling of the Americas. Obsidian—a volcanic glass was widely used by prehistoric people to manufacture tools—has unique chemical fingerprints, specific to individual volcanoes, that allows artifacts made from obsidian to confidently be assigned to their geologic source. By sourcing archaeological obsidian to the volcano where it was produced, the Smithsonian’s Museum Conservation Institute in collaboration with National Museum of Natural History researchers hopes to identify the earliest movement of obsidian and people between Northeastern Russia and the Americas. Using portable X-ray fluorescence and laser ablation-inductively coupled plasma-mass spectrometry to identify the chemical fingerprints of obsidian artifact from museum and research collections, MCI is tracing the movements of prehistoric people and examining the trade networks and social interaction across present-day Alaska and eastern Siberia.
Conserving our nation's treasures
Continuing a long standing practice of more than four decades, in October 2006, staff of the Smithsonian's Museum Conservation Institute (MCI) examined, analyzed, and conserved the Mace of The United States House of Representatives. The work was completed on an extremely tight schedule during the pre-election recess so that the Mace could reassume its official place next to the Speaker's Dais, as its presence is required in order for the House to convene. Disassembly of the Mace and removal and reapplication of its protective coatings allowed scholarly assessment of the master silversmithing and construction dating from the object's creation in 1841, and scientific analysis of the aggressive corrosion that had suddenly plagued the silver and ebony artifact in the 2000s. Noteworthy observations included the probable source of the sudden purplish tarnishing (likely exposure to chlorine dioxide in the airborne environment), and the fabrication method of its large hollow silver globe (cast as a sphere, rather than formed from raised and soldered silver sheet hemispheres.) The protective coating applied to the ebony rods was the MCI-patented furniture polish developed in accordance with the exacting standards of conservation care. The need for an appropriate and effective protective coating for the silver launched a new research project the results of which will be reported in an upcoming publication.
Deterioration modern materials - finding the cause, finding the cure
Modern materials, especially synthetic polymers and plastics, had a significant influence on industrial, domestic and cultural life through the 19th and 20th centuries. The Smithsonian's museums and collections are depositories for many different forms of modern materials, from fine arts in the Cooper-Hewitt and Hirshhorn museums to industrial objects in the National Air and Space Museum and National Museum of American History (NMAH). Now some of these modern materials are exhibiting signs of deterioration; past exposure to light, heat, moisture, chemical, and gaseous pollutants are reducing their integrity and longevity. The Smithsonian’s Museum Conservation Institute’s (MCI) modern materials program is examining the deterioration of polymers and plastics in industrial plastics, painting varnishes, conservation adhesives, and sculpture coatings. In one project, MCI researchers have studied a set of 1930s Lumarith cellulose acetate samples from the Division of Medicine and Science of the NMAH to discover why a few of the 49 color samples on a salesman's ring are weeping and crizzling. This research is reported in Studies in Conservation. With a better understanding of these materials and their degradation, MCI will help Smithsonian museums find ways to extend the longevity of 19th and 20th century art and objects.
New and improved analysis for modern paintings and pigments
Artists’ pigments are a source of information for understanding and safeguarding art objects. They are key elements in dating paintings and painted objects, attributing them to artists, and detecting fakes and forgeries. Their chemical identification is also crucial for finding safe conservation treatments and environmental conditions for display, storage, and transport of valuable art. Modern synthetic organic pigments and paint formulations are rife with problems — aging, cracking, fading — that are different from those of traditional painting materials. Therefore, it is vitally important that these modern pigments, along with their synthetic binders and additives, are characterized before problems arise. The Smithsonian’s Museum Conservation Institute scientists and fellows, in collaboration with international colleagues, have developed complementary analytical methods using X-ray diffraction and Raman spectroscopy that together allow improved identification of these modern synthetic organic pigments in acrylic and alkyd paint formulations and oil media, respectively. Raman spectroscopy, as a non-invasive and portable technique, allows the analysis to come to the painting. This research will be reported in an upcoming issue of the journal Analytical Chemistry.
MCI repairs and conserves Rosa Parks' dress
On December 1, 1955, in Montgomery, Alabama, Ms. Rosa Parks was riding a public bus and thinking about finishing a new dress. Ms. Parks, a professional seamstress, was sewing a dress for herself this time. Her thoughts were interrupted by an order, and her refusal, to relinquish her seat on a segregated bus. That refusal and her subsequent arrest led to the famous 382 day long Montgomery, Alabama boycott and became an important symbol of the modern Civil Rights Movement. Now the dress itself will become an icon of the new National Museum for African American History and Culture (NMAAHC). The delicate rayon georgette print dress made its way into NMAAHC in 2007 through the new museum’s acquisition of the Black Fashion Museum (BFM), of Washington, DC, and on to the Museum Conservation Institute (MCI) for conservation. By the time it arrived at MCI, it had acquired numerous small but disfiguring tears. Under the guidance of MCI’s senior textile conservator, conservation interns repaired the tears using dyed chiffon and a fine silk thread called ‘hair silk’, also dyed to match, in a couching stitch to follow the grain of the weave. Following a careful regime of anoxic pest-control treatment, cleaning, photography, accessioning, repair and re-housing, the dress is now fit for exhibiting.
Ms. Rosa Parks’ dress is one of the BMF’s estimated 700 garments, 150 hats, 100 pairs of shoes, 50 handbags, and nearly 60 boxes of photographs, files, and ephemera. BFM’s collection was founded in 1979 by Lois K. Alexander-Lane with a mission to collect costumes of American designers of color, and later included costumes worn by well-known African Americans or in theatrical productions with African-American casts. MCI in a partnership with NMAAHC is providing conservation and scientific analysis for this major acquisition.–The project’s goal is to preserve BFM’s priceless costumes, and to re-establish this collection as an accessible, researchable, entity that is a unique asset to NMAAHC and the Smithsonian Institution. In the process, MCI conservators are providing training to the museum’s growing staff in conserving and studying this important collection.
Pre-Columbian gold is evidence for the spread of metalworking technology across the Panamanian Isthmus
Pre-Columbian gold artifacts are appreciated for their beauty and impressive craftsmanship. Yet, Panama’s contribution to this rich heritage is not well understood. As a narrow bridge between the Americas, it is the only corridor for the movement of goldworking technology from northern South America, where it first emerged, to Mesoamerican and central Mexican regions. By about 200 CE, goldworking technology had reached the Isthmus, and this early goldwork from Panama emulated metalworking centers in today’s Colombia. Over time, however, a splendid Panamanian style developed, epitomized by the impressive gold adornments of high-status males buried at the Sitio Conte cemetery, dating from between 700 and 1000 CE; many centuries later, ornaments similar to these were described by the Spaniards related to a chieftain’s burial.
While metalworking production in neighboring centers has received considerable attention, no systematic study has been carried out on Panama’s contributions. To bridge this gap, the Smithsonian’s Museum Conservation Institute (MCI), in collaboration with the Smithsonian Tropical Research Institute (STRI), the National Museum of Natural History (NMNH) and the National Museum of the American Indian (NMAI), is studying gold collections in Panama and in the Smithsonian Institution collections. The gold is from two STRI excavations, including nearly 100 items from the site of Cerro Juan Díaz, a village and funerary precinct (Azuero Peninsula) and new finds from El Caño, an elite burial ground adjacent to Sitio Conte (Coclé province); Smithsonian collections of 74 and 208 accessioned items at NMNH and NMAI, respectively; and 575 objects in the collection of the Museo Antropológico Reina Torres de Araúz [MARTA], Panama’s premier archaeological museum. This project brings together the perspectives and skills of the conservator, conservation scientist, goldsmith, and archaeologist, and features non-destructive techniques, such as X-ray fluorescence spectroscopy and optical microscopy, with more in-depth analytical techniques, where sampling has been permitted. Understanding the technological of Panamanian goldworking – using information about alloy composition, forming, and finishing techniques – will illuminate the origins, development, and regional relationships of Panamanian goldworking, complementing iconographical, archaeological, and ethnohistorical lines of evidence.
Second Annual Conservation Conference celebrates the research contributions of fellows and interns
Every year the conservation and conservation science programs throughout the Smithsonian host many fellows and interns. Whether these fellows and interns are at the Smithsonian for a few weeks or a few years, they significantly increase research and conservation treatment productivity. For the second year, the Smithsonian Conservation community has sponsored a one-day symposium held at the Smithsonian’s Museum Conservation Institute where fellows and advanced interns in Conservation and Conservation Science present their research topics and preliminary results. Smithsonian Secretary Wayne Clough opened the conference with a warm welcome to the fellows and interns. Nine of the fellows and interns, representing four of the Smithsonian’s units, presented their research results on topics ranging from materials analyses of paintings at the Hirshhorn and glass beads on costumes at the National Museum of African Art, fabrication and provenance studies of pre-Columbian Gold excavated by the Smithsonian Tropical Research Institute and colonial ceramics at the National Museum of Natural History (NMNH), to the ethnographic use of dog hair in Salish blankets at the National Museum of the American Indian and NMNH and historic use of synthetic dyes including indigo in textiles.
The annual conference brings together the far-flung professional conservators and conservation scientists of the Smithsonian. This group of 76 full-time staff members is spread across 16 museums, units, or research institutes, located in Maryland, New York, and the District of Columbia. Professional conservators preserve cultural heritage through examination, documentation, treatment and preventive care; conservation scientists apply specialized scientific knowledge and technical skills to understand cultural heritage and its material properties and interpret scientific data to inform conservation and preservation. The conference is important to the Smithsonian’s conservation community to keep them informed of research advances and enhance their professional development.