Engineers Help to Save and Reconstruct the Past

Each time an ancient vase disintegrates, a ceramic tile crumbles or a painting cracks and fades, another link with our past is lost and we understand just a little less about where we came from and, ultimately, who we are.

When the last artisan dies and an ancient technology is lost, we're similarly impoverished, says Pamela Vandiver, an internationally recognized expert in artifact preservation and, now, a professor at The University of Arizona.

Vandiver came to UA last year to start a program in Heritage Conservation Science (HCS) that trains students to stabilize, preserve and better understand ancient artifacts and how they were created and used.

The curriculum, which combines engineering, anthropology, architectural history and art history is particularly important today because many of the material links to our past are disintegrating, while the ancient technologies that created them are disappearing.

"To preserve our inheritance, we really need a group of scientists and engineers who can work with conservators and other experts to stabilize and preserve these objects," says Vandiver, who holds a joint appointment in Anthropology and in Materials Science and Engineering (MSE).

Professor Pamela Vandiver talks with a student during a lab class on flint knapping.

Knowing how these objects were made is just as important as preserving them, she added.

We might wonder what there is to understand. After all, we live in a high-tech, materials-oriented culture that can produce everything from ceramic heat shields for space shuttles to atom-sized electronic circuits. So there can't be much we don't know about making things, right?

“Wrong,” says Vandiver. For instance, the glazes on 10th to 12th century Chinese ceramics are a mystery. They're at the top of the heap in terms of stable, high-fired ceramics. But modern potters can't reproduce them.

In another case, we didn't understand the technology behind 12th century ceramics made at the recently excavated imperial kilns in Angkor Wat until last year when Vandiver and her Cambodian colleagues unraveled the process.

Khmer potters fired a quartzite-rich ceramic body and then re-fired the ceramic using a Chinese-style glaze. It was either a high-lime, green celadon glaze or a high-lime and iron brown glaze. The glazes were fired to between 1,800 to 2,000 degrees Fahrenheit. Celadon glazes have a translucent quality that is meant to resemble jade.

This ancient Cambodian technology now is being taught to local potters who are keeping it alive by producing reproductions of the 12th-century ceramics.

Heritage Conservation Science involves learning how artifacts are handcrafted. A student made this glass vase during a lab that explored the technology of glass blowing.

The technology has been so exactly replicated that "some of the border guards have started to intercept these new ceramics because they look exactly like the old ones," Vandiver says. "So we have succeeded in re-creating an important technology and keeping it alive."

Preserving ancient technologies is so important that UNESCO recently started an international program to preserve craft knowledge, Vandiver says. The program is similar to the one that designates World Heritage Sites.

Vandiver came to UA because much of the basic infrastructure needed to start an HCS program already existed on campus. Architecture has a degree in architectural preservation. Archaeology is a strong discipline at UA, and the university has world-recognized tree-ring and carbon-dating labs. The Arizona State Museum is a center for conservation of Southwestern artifacts, and UA has materials-based studies in art history, chemistry, classics, geosciences, and Near Eastern studies.

In addition, UA has a long history of socio-cultural studies and interdisciplinary cooperation between the MSE Department, Anthropology and other programs.

For Vandiver, UA was the ideal location to transfer her work after 18 years as a senior research scientist at the Smithsonian and as a MSE faculty member in the cultural heritage program at Johns Hopkins University.

The Johns Hopkins program was discontinued when two key professors retired, and Vandiver also found herself being kicked upstairs into administration at the Smithsonian.

"So I couldn't go on excavations, couldn't work in the lab, and couldn't work with students," she says. "It was getting more and more frustrating all the time."

She knew about the critical mass for heritage conservation science at UA because her former Ph.D. thesis supervisor, the late David Kingery, was on the UA MSE faculty for many years and organized collaborative research on historic preservation.

So she decided to follow her passion, discarding a prestigious senior position at the Smithsonian to start a new program at UA.

"We're trying to put materials science education at the core of historic preservation, rather than just wallpapering over an archaeologist or conservator with a few materials science courses," she says. "We are producing students who are truly dual disciplinary."

Currently, she and her students are working on several projects. These range from studying lost glazing technologies used on 12th-century Chinese pottery to unraveling the mysteries of a Hopi pottery style.

The projects also include studying adobe-making technologies and constructing kilns to better understand glass slags and Greek pottery. Another project involves studying the basic physics related to cleaning artifacts with lasers. To read more about these projects, click here.

Anthropology master's student Ned Gaines demonstrated flint knapping, a method for making stone tools, during a lab in MSE 257, one of the classes in the new Heritage Conservation Science Curriculum.

UA Heritage Conservation Science Research Projects

Professor Pamela Vandiver and her students and colleagues are working on several research projects. They include: These pottery sherds have Ru glazing.

• Chinese Ru Glazes — MSE student Alix Deymier and Vandiver are analyzing Ru glazes on Chinese Song Dynasty (10th to 12th century) imperial ceramics. "On this project, as with all such work, we are looking through a veil of weathering and working back through the technology to the raw materials," Vandiver says.

This involves interconnected processes that the researchers need to analyze and deconstruct. They need to understand the effects of materials corrosion and weathering, as well as the technology of how these things were made and used. Other factors include previous restoration efforts and the effects of long storage or burial at an archaeological site.

Alix Deymier is using the scanning electron microscope in UA's Materials Science and Engineering Department to study the microstructure of Ru glazes.

"Often, the samples we have to work with are tiny, measuring maybe 20 cubic microns, and we need to process these through several analytical tests," Vandiver says.

• Sitkyatki Pottery — Vandiver and MSE grad student Caitlin O’Grady, are studying a particularly elegant type of Hopi pottery, called "Sitkyatki polychrome." It's often called the "Porcelain of the Southwest."

To understand both the high-fired ceramic technology that created it and the factors that have caused it to be so well preserved, she is using the same analytical methodology she used with the Cambodian ceramics. This involves characterizing composition, microstructure and firing temperature of both the ceramic body and the four different colors of slip-glazes.

O'Grady will be using local materials to reproduce some parts of the firing process that are particularly difficult to understand and that require a nuanced, experimental approach.

• Glass Slags — MSE grad student Dan Jeffery is studying the behavioral similarities in glass slags that result from smelting several different types of metals. These include tin, copper, iron and lead. Even though the compositions and temperatures of the smelting processes are different, the slag viscosities may be similar.

For the tin and copper, he is modeling his studies on traditional technologies used in the second and third millennia B.C. at the Near Eastern sites of Goltepe in Turkey, Tell Feinan in Jordan and Timna in Israel.

For the iron, he is characterizing 17th century early Industrial Revolution slags from New England and Scotland.

For the lead, he is using slags produced by a new process being developed in England. It is designed extract lead when CRT and TV-screens are recycled.

Jeffrey has built traditional furnaces for smelting iron and copper and will be testing them in the next few weeks.

Both O’Grady and Jeffery have received Gutmann Foundation grants for conservation science research and recently have been awarded prestigious NSF IGERT one-year fellowships in archeological science.

• Laser Cleaning Technology — Vandiver also is collaborating with Associate Professor Kelly Potter, of Electrical and Computer Engineering, on how to use lasers to clean old coatings from artifacts. In the 1950s, for instance, a soluble nylon was used to coat artifacts. Conservators now recognize that this can damage artifacts and that these nylon coatings need to be removed.

"We are looking at how the laser alters the composition of a material as the coating is removed," Vandiver says. "We're trying to find out what's happening at a molecular level. No one has ever done that. Instead, they've cleaned with a laser and said, 'OK, that looks right,' but we don't know if we're altering or damaging these artifacts until we really understand compositional and microstructural transformations."

Adam Grochowski is analyzing brick and mortar from Tucson's 18th century presidio wall and from the Old Adobe Brick Co. • Adobe Making — Vandiver and MSE student Adam Grochowski are analyzing brick and mortar from Tucson's 18th century presidio wall and from the Old Adobe Brick Co. to understand the differences and why these materials are different.

Some of the results from this work are being applied to analyzing ancient adobe bricks at the Chevelon and Homolovi sites in Northern Arizona. Vandiver and Grochowski are collaborating on this research with Lisa Gavioli, an archaeology grad student, and Professor Chuck Adams, curator of archaeology at the Arizona State Museum.

• A Greek Kiln — Vandiver and her students are working with Assistant Professor Eleni Hasaki, of the UA Classics Department. They're providing technical support for an effort to construct a wood-burning kiln. It's a replica of a Greek kiln used in the 4th century B.C.

• Tohono O'Odham Pottery — Vandiver also is working with Tohono O'Odhom potter and UA grad student Reuben Naranjo to better understand the traditional materials and techniques used for making pottery in the Tohono O'Odhom community near Tucson.

These pottery sherds have Ru glazing.

Alix Deymier is using the scanning electron microscope in UA's Materials Science and Engineering Department to study the microstructure of Ru glazes.

Adam Grochowski is analyzing brick and mortar from Tucson's 18th century presidio wall and from the Old Adobe Brick Co.

Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.