Conservation student Kate Brugioni blows the lid off the restoration process for ancient Egyptian artifacts

Editor’s note: This fall some changes are coming to the HMNS Hall of Ancient Egypt. Some artifacts will leave and others are coming in on new loans. As we prepare for this, NYU third-year art conservation student Kate Brugioni will take us through the restoration process for ancient artifacts. 

When you walk around the Hall of Ancient Egypt, you see some pretty old stuff — actually some really old stuff. We’re talking thousands of years here, folks. But have you ever wondered how everything stays in top condition? 

Well that’s my job (rather, summer internship, but it will be my job soon)!

I’m Kate Brugioni, rising third-year art conservation student at the Conservation Center, Institute of Fine Arts at NYU. My education combines a study of art history, archaeology, museology and science. After completing this rigorous four-year program, I will graduate with a Master’s degree in Art History and an Advanced Certificate in Conservation.

As a student with a particular interest in painted wood surfaces, I am excited to be treating the Carlos Museum‘s polychrome-wood coffin lid, dated to the 22nd–24th dynasties of Ancient Egypt (943–720 BCE). More than 500 hours of documentation, study, and treatment will be completed over the course of this project, and I would like to share something of the sense of excitement and discovery this opportunity has brought me.

Photograph by Ashley Jehle.

Kate Brugioni and Renée Stein examining the reverse side of the coffin lid.

One of the most striking features of this anthropoid coffin lid is the ancient wood, largely left uncovered to showcase its fine texture; the painted wsh (“broad”) collar; and offertory inscription down the center. Of special interest are the features original to the coffin construction, such as dowels, mortise and tenon structures, an ochre-colored preparation layer and painted decoration. Over the course of treatment, these will be carefully documented, cleaned and stabilized.

Although the arid Egyptian climate preserved much of the wood substrate, diffuse fungal deterioration, abrasion, and flaking has affected the structure and appearance of the coffin lid. Additionally, a number of invasive “restoration” campaigns has damaged the ancient surface and structure.

The important second step of this project will be to locate and characterize these restoration materials, and deciding how they could be best reversed, where appropriate

Photo by Kate Brugioni.

Ancient Egyptian Coffin Lid (obverse). 22nd-24th Dynasty (MCCM.2011.01). Before treatment.


Photo by Kate Brugioni.

Ancient Egyptian Coffin Lid (reverse). 22nd-24th Dynasty (MCCM.2011.01). Before treatment.

Thank you for reading, and please stay tuned to this blog for up-to-date information about our findings over the course of treatment.

Oh, and one more thing! I would like to thank the Houston Museum of Natural Science for so generously supporting my summer internship at the Parsons Conservation Laboratory at the Michael C. Carlos Museum at Emory University, where I am preparing an ancient Egyptian coffin lid for long-term loan to the Hall of Ancient Egypt at HMNS.

We’d like to introduce you to the four new species of African house bats

Editor’s note: This blog post is a summation of “New Species of Scotophilus (Chiroptera: Vespertiliondae) from Sub-Saharan Africa,” written by HMNS Curator of Vertebrate Zoology Daniel M. Brooks and John W. Bickham, and published as a monograph in the Occasional Papers of the Museum at Texas Tech University.

Sub-Saharan Africa is a hotbed of biological diversity. A seemingly endless stream of new species has been discovered from different locales every year for centuries. The idea of this great biodiversity is widely accepted and, in fact, celebrated. But advances in genomic sequencing and morphology and an increased ability to obtain reliable specimens while recording their location shows that we’ve really just hit the tip of the iceberg. Many individual clades (or groups) of species should actually be distinguished further from each other as unique species themselves.

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Distribution of the four new species in Africa

The conservation question

Hold on a second here. Why is this important? What kind of difference could it make if there are 15 or 19 or 30 species of house bats in the world?

Glad you asked! Having an accurate taxonomy (naming and classification system) guides conservation efforts, while incomplete records impede these same efforts. Look at it this way: if you don’t know that a species exists, how can you protect it? In our modern era, we’re seeing rapid climate change and urbanization, which puts habitats under stresses to which species cannot quickly adapt. Therefore, having complete records allows us to make more meaningful conservation efforts because we have a better picture of what we’re trying to conserve. Having an accurate taxonomy also helps us to learn about biogeography, evolution, biodiversity and biology in general.

Now on to the bats!

As of 2005, there were 15 species of Scotophilus (house bats) documented. These were distributed between Indonesia, mainland Asia, Madagascar, Reunion Island and mainland Africa. However, these 15 species do not accurately reflect our current knowledge of Scotophilus biodiversity.

A 2009 study by Robert G. Trujillo sequenced cytochrome-b (part of an organism’s DNA) in Scotoplilus. Cytochrome-b is found in mitochondrial DNA, which is the genetic material in mitochondria (the “energy factory” of cells, if you will). These sequences are very useful in determining species differentiation.

With this information, Trujillo identified four distinct clades (branches on a species family tree). These include clades 8, 9, 11 and 12. Brooks and Bickham examined specimens from each of these lineages to see if there were enough physical differences between the organisms to further classify them as distinct species.

The clades and species of Scotophilus studied for the mitochondrial cytochrome-b gene by Trujillo et al. (2009). The new species described in this  paper are circled.

The clades and species of Scotophilus studied for the mitochondrial cytochrome-b gene by Trujillo et al. (2009). The new species described in this paper are circled.

Brooks and Bickham used skull and body measurements to compare specimens of each lineage with specimens representing the appropriate nominate — “textbook specimens” — of a given species).

Basically, they got very specific: measuring specimens from one predetermined area, and compared them to the nominate “textbook specimens” to see what physical differences there may or may not be.

When they compared the specimens, we saw that the genetic differences between the clades matched up with physical differences, which is why I’m proud to introduce to you four new species of African house bats (Scotophilus)!

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Study skin of Scotophilus andrewreborii holotype

 

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Study cranium and mandible of Scotophilus andrewreborii holotype

Scotophilus andrewreborii
Andrew Rebori’s House Bat

It is our honor to name this species for Andrew N. Rebori (1948–2011). Rebori unknowingly touched lives and inspired many individuals, including many museum professionals. He always maintained a keen interest in animals, especially bats, which exemplified his spirit and attitude toward life: “Take flight every new day!”

Type locality: Kenya: Rift Valley Province, Nakuru District, 12 km S, 4 km E Nakuru (0º24′S, 36º07′E).

Diagnosis: Scotophilus andrewreborii is distinguished from S. dinganii from Natal by a combination of external and craniodental features. S. andrewreborii averages slightly larger in body size for most characters. Additionally the dorsal pelage in S. andrewreborii is more reddish than the browner dorsal fur of S. dinganii, and the ventral pelage in S. andrewreborii is orange versus a much darker grey in S. dinganii.

Cranial measurements in S. andrewreborii are smaller, with non-overlapping measurements for braincase breadth for males, and shorter mean skull length (18.9 in S. andrewreborii vs. 19.6 mm for S. dinganii), narrower zygomatic, shorter braincase height, narrower interorbital width (4.4 vs. 4.8 mm), decreased breadth across upper molars, and decreased breadth across upper canines for females.

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Study skin of Scotophilus livingstonii holotype

 

Study cranium and mandible of Scotophilus livingstonii holotype.

Study cranium and mandible of Scotophilus livingstonii
holotype

Scotophilus livingstonii
Livingstone’s House Bat

It is our honor to name this species for the late David Livingstone (1813–1873). At a time when most of Africa was barely known compared to today, Livingstone, a young Scot of humble means, explored central Africa. Between 1841 and his death in 1873, Livingstone made several expeditions into the interior of the continent, mapping uncharted lands and searching for navigable waterways.

Type locality: Kenya: Western Province, Kakamega District, Ikuywa River Bridge, 6.5 km S, 19 km E Kakamega (0º13′N, 34º55′E).

Diagnosis: Scotophilus livingstonii is distinguished from S. dinganii from Natal by a combination of external and craniodental features. S. livingstonii averages larger overall in body size. Additionally the dorsal pelage in S. livingstonii is more reddish-mahogany than the browner dorsal fur of S. dinganii, and the ventral abdominal pelage in S. livingstonii is light buff vs. a much darker grey in S. dinganii.

Scotophilus livingstonii is also distinguished from S. dinganii from Natal by cranio-dental measurements. Male S. livingstonii have a shorter mean skull length, and females have a longer mean mandibular length.

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Study skin of Scotophilus ejetai holotype

 

Study cranium and mandible of Scotophilus ejetai holotype.

Study cranium and mandible of Scotophilus ejetai holotype

Scotophilus ejetai
Ejeta’s House Bat

This species is named in honor of Dr. Gebisa Ejeta, Distinguished Professor of Plant Breeding & Genetics and International Agriculture at Purdue University. He was born and raised in the village of Wollonkomi in west-central Ethiopia. Dr. Ejeta is a plant breeder and geneticist who received the 2009 World Food Prize for his research and development of improved sorghum hybrids resistant to drought and Striga weed. The results of his work have dramatically enhanced the food supply of hundreds of millions of people in sub-Saharan Africa.

Type locality: Ethiopia: Orimaya Region, Dogy River Bridge (8º21’43″N, 35º53’02″E). Collected at 1390 m above sea level.

Diagnosis: Scotophilus ejetai is distinguished from S. dinganii from Natal by a combination of external and craniodental features. S. ejetai averages smaller overall in body size, with females presenting non-overlapping forearm length.  Additionally the ventral pelage in S. ejetai has an orange hue, whereas the ventral fur is buff with a greyish abdomen in S. dinganii.

Cranial measurements in S. ejetai are smaller, with non-overlapping measurements for skull length, zygomatic breadth and braincase breadth for males, and zygomatic breadth and braincase breadth for females.

Study skin of Scotophilus trujilloi holotype.

Study skin of Scotophilus trujilloi holotype

 

Study cranium and mandible of Scotophilus trujilloi holotype.

Study cranium and mandible of Scotophilus trujilloi holotype

Scotophilus trujilloi
Trujillo’s House Bat

It is our honor to name this species for Dr. Robert Trujillo (b. 1975), whose ground-breaking doctoral dissertation on the molecular systematics of Scotophilus paved the way for the description of the four cryptic species described here. Dr. Trujillo’s dedication to science and environmental stewardship are reflected in his outstanding career in the US Forest Service.

Type locality: Kenya: Coastal Province, Kwale District, Moana Marine Station, 1 km S, 2 km E Ukunda (4º18′S, 39º35′E).

Diagnosis: Scotophilus trujilloi is distinguished from S. viridis from Mozambique Island by a combination of external and craniodental features. S. trujilloi averages larger in body size and shorter in forearm length, with females presenting non-overlapping head-body and forearm lengths. Additionally the dorsal pelage in S. trujilloi is mahogany, whereas the dorsal fur is brown in S. viridis. The ventral pelage in S. trujilloi is orange with a greyish abdomen, whereas the ventral fur is grayish-brown grizzled whitish abdominally in S. viridis.

Cranial measurements in S. trujilloi differ from S. viridis, with shorter mean braincase height in males; and females, as well as non-overlapping mandibular length in females. 

Preserving Egypt’s cultural past: A conversation about conservation with Dina Aboul Saad

Editor’s Note: Today’s post was written by Dina Aboul Saad, Director of Development at the American Research Center in Egypt.

ARCE Collage

Ancient Egyptian, Roman, Coptic and Islamic sites further our understanding of the rich cultural history of Egypt, but there’s much more to Egypt than digging up artifacts. Have you ever thought about what happens to the sites and objects once they are uncovered? And why do we endeavor to preserve Egypt’s cultural past?

The American Research Center in Egypt (ARCE) answers these questions through the most extensive program of conservation and training in Egypt today. In recent years the American Research Center in Egypt (ARCE) has conducted large-scale preservation and training activities at important archaeological sites throughout Egypt in collaboration with Egyptian colleagues and the Ministry of State for Antiquities.

On Nov. 7th at HMNS, you have an opportunity to see some of the iconic sites ARCE works to conserve and document.

fruitcake egypt

Working in Egypt since 1948, ARCE supports scholarly research in Egypt in a variety of areas including archaeology, training, site documentation and mapping, and conservation.

Brian Eno, the British rock musician and avant-garde artist, once remarked, “We are convinced by things that show internal complexity; [things] that show the traces of an interesting evolution. That is what makes old buildings interesting. Humans have a taste for things that not only show that they have been through a process of evolution, but which also show they are still part of one. They are not dead yet.”

We feel disconnected when the opportunity to involve ourselves with cultural history, even from a distance, is taken away.

Don’t miss Dina’s presentation, where she will give an overview of ARCE’s archaeological projects and the impact these projects have in Egypt. This event is co-sponsored by the Egyptian American Society of Houston here at HMNS on Thurs., Nov. 7 at 6:30 p.m. For advance tickets, call 713-639-4629 or get them online.

Copper, corrosion and curbing the damaging effects of Bronze Disease

Editor’s Note: Alexis North is a third-year graduate student in Conservation of Archaeological and Ethnographic Materials at UCLA. She specializes in the conservation of archaeological objects and is working at the Michael C. Carlos Museum at Emory University this summer, preparing a group of objects for display here at HMNS. Read the first blog from her series here.

You may think of metal as a strong, impervious material. It’s used in bridge and building construction, and many of the tools we use today are made of metal (like silverware, hammers and screwdrivers, medical scalpels, etc.). Despite its strength, however, metal can be one of the more fragile materials found in archaeological sites. This is because different types of metal can very easily corrode in the presence of moisture and salts, both of which are found in the burial soils of archaeological sites. If you’ve ever seen red rust on an iron fence, or an old penny turn green, then you’ve seen what corrosion can look like.

Five of the objects I am working on this summer are made of copper alloy. An alloy is a mixture of metals. Copper is most often alloyed with silver, tin, arsenic or lead (or any combination of those) and the resulting mixture will have different strengths and working properties depending on the components and the proportions of those components. Here at the conservation laboratory at the Carlos Museum, one way we can determine which metals are present in an alloy is by using X-ray fluorescence spectroscopy (XRF).

XRF analysis uses X-rays to excite the electrons within a material. These electrons jump to a higher energy level when they come into contact with the X-rays. The electrons of each element give off a characteristic amount of energy when they return to their unexcited state.

By measuring the amounts of energy emitted, we can determine which elements comprise a certain object. Here, the XRF spectrum of the cat figurine seen in my first blog post shows that the metal is an alloy of copper (Cu) and lead (Pb), with a possible trace amount of silver (Ag). The iron (Fe) most likely comes from the burial environment.

Copper, corrosion and curbing the damaging effects of Bronze DiseaseXRF spectrum of 1999.001.043, revealing copper and lead as major components.

Copper and its alloys are susceptible to several different types of corrosion, some of which are good or protective corrosion, and some of which can be very damaging to the objects. After a copper alloy object is buried, it forms a protective layer of copper oxide (cuprite) on its surface. Cuprite can be bright to deep red in color, and will preserve the original surface of the object, even when additional corrosion layers form on top. That upper layer of corrosion is usually made of copper carbonates, called malachite and azurite. These compounds are bright green and blue in color, respectively, and have historically been used as pigments, in Egypt and elsewhere.

The real bad boys of copper corrosion are the copper chlorides. These appear as a pale turquoise green compound, usually in spots on the metal’s surface. When copper metal comes into contact with chloride anions, it forms deep pits full of copper chlorides. These pits disrupt the metal’s surface, damaging the original appearance of the object and obscuring surface details. These pits are also autocatalytic, meaning that once one appears, it will continue to grow and form additional pits until the copper chlorides are removed. This cycle of corrosion is commonly called “Bronze Disease,” like a kind of copper Chicken Pox!

Copper, corrosion and curbing the damaging effects of Bronze DiseaseSchematic diagram of copper alloy object with various types of corrosion products.

All five copper alloy objects that I am working on show evidence of Bronze Disease, as well as malachite and cuprite formations. The cat figurine has very little corrosion, and will not require much treatment at all before it will be ready to pack up and ship to the HMNS. This mirror, on the other hand, has significant corrosion all over its surface. In the detail image on the right, you can see where I’ve found an area of Bronze Disease, and the powdery light green copper chlorides are erupting onto the surface.

Copper, corrosion and curbing the damaging effects of Bronze DiseaseBefore treatment image of copper alloy mirror (left) and close-up image of Bronze Disease pit with copper chloride corrosion products (right).

Treating Bronze Disease is a two-step process. First, the copper chlorides must be mechanically removed. I do this using a variety of tools, including scalpels and dental tools (if they work for cleaning your teeth, then they should work for cleaning copper!). The copper chlorides are gently scraped away, while making sure that I don’t damage the rest of the mirror’s surface. The pits made by the copper chlorides are carefully cleaned out, so they can then be chemically treated to help prevent the formation of new copper chlorides. Once the corrosion products have been removed, the objects are treated with Benzotriazole (BTA), a corrosion inhibitor that forms a stable coating with the superficial copper ions, so they cannot react with any chloride ions which may come around.

Corrosion cannot be stopped completely, but these treatments help to significantly slow down the deterioration process, allowing the objects to continue to be displayed and studied. While the corrosion may not be vanquished entirely, with careful consideration the right conservation treatment can be undertaken, allowing these objects to be enjoyed both by scholars and museum visitors like you for many years to come!

References:
“Benzotriazole,” Conservation and Art Material Encyclopedia Online (CAMEO), Museum of Fine Arts, Boston, http://cameo.mfa.org/wiki/Benzotriazole, accessed 7/16/2013
Scott, David A. Copper and Bronze in Art: Corrosion, Colorants, and Conservation. Los Angeles: Getty Publications, 2002.