APPEAR Project – X-Ray Radiography of the Fayum Mummy Portraits

Hi! This is Eve Mayberger with more information about the Ancient Panel Painting: Examination, Analysis, and Research (APPEAR) project. During the past few months, I have been investigating the three Fayum mummy portraits in the Penn Museum with digital photography, multispectral imaging (MSI), portable x-ray fluorescence (pXRF), and most recently x-ray radiography.

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APPEAR Project, Processing the x-ray radiographs

X-ray radiography is an incredibly useful technique to understand different materials, manufacturing techniques, later alterations, and condition issues. The x-ray radiograph of the Portrait of a Young Man (E16213) illustrates tool marks characteristic of the encaustic technique. The pigmented wax is worked warm and one can see the individual brush strokes. The background is made with a wide brush while the face is heavily worked with small tools to create the delicate shading in the flesh tones.

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APPEAR Project, Portrait of a Young Man (E16213); Digital photography; Digital x-ray radiography (36 kV 6mA 6s)

X-ray radiography can help record decorative elements that are difficult to see and documented under normal conditions. The gold frame around the Portrait of a Boy (E16212) is ornamented with raised decorations. The sheen of the gold and the later surface alterations make it difficult to see the overall design; however, the decoration is easily discernible on the x-ray radiograph. It is also interesting to note that the wood grain is visible.

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APPEAR Project, Portrait of a Boy (E16212); Digital photography; Digital x-ray radiography with annotation (36 kV 6mA 6s)

Sometimes x-ray radiography can show alterations to the surface or substrate. The Portrait of a Woman (E16214) shows that the artist decided to change the outline of the face. The annotated image highlights how the contours of the of the woman’s face was changed to give her a fuller cheek. Observe that the dark resin circle around the face is not visible in the x-ray radiograph. It is important to remember that not all materials (especially if they are of different densities) can be shown in a single radiographic image.

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APPEAR Project, Portrait of a Woman (E16214); Digital photography; Digital x-ray radiography with annotation (36 kV 6mA 6s)

Be sure to visit the blog in the upcoming weeks to read more about the APPEAR project!

Eve Mayberger, Curriculum Intern

What’s inside those animal mummies?

Last week we x-rayed 8 animal mummies from our collection. These mummies were previously in storage and are in the Artifact Lab for much needed treatment and storage upgrades. As you can see in the images below, some of them are incredibly fragile with extensive damage. X-radiography is completely non-invasive and is one of the best tools we can use to study these mummies.

Recently we heard that researchers at the Manchester Museum and the University of Manchester found that about 1/3 of their mummies are “fakes” (and we use this word rather loosely – read the article in the link to find out more).

How do ours measure up? Well, even though we have a much smaller sample size, we found our stats to be a little bit better – 7 of the 8 that we just x-rayed contain animal remains, and one contains the remains of 3 animals, so the number of animals actually outnumbers the number of mummies in this instance!

Below we’ve posted paired images of the animal mummies and their radiographs. Our initial findings are written in the captions for each image. See if you can figure each one out, and if you see something that doesn’t make sense or something that we haven’t explained, please write into the comments below this post and we’ll follow up! All radiographs were captured with a GE Inspection and Sensing Eresco 65MF4 tube on a digital x-ray detector at 35kV 6mA for 6 seconds.

Cat mummy (left) and x-ray image (right) showing a complete cat body inside.

L-55-13: Mummy (left) and radiograph (right) showing a complete cat body inside.

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97-121-27: Mummy (left) and radiograph (right) showing an ibis in the lower 2/3 of the wrappings.

Mummy (left) and radiograph (right) showing a fragmented ibis body inside.

97-121-28: Mummy (left) and radiograph (right) showing fragmented ibis remains inside.

Mummy (left) and radiograph (right) showing an ibis inside.

E3539: Mummy (left) and radiograph (right) showing an ibis inside.

Mummy (left) and radiograph (right) showing an ibis inside, plus an extra bone and part of the ibis beak.

E3541: Mummy (left) and radiograph (right) showing an ibis inside, plus an extra bone and part of the ibis beak lying outside the mummy bundle.

Mummy (left) and radiograph (right) showing nothing inside the wrappings.

CG2015-4-1080: Mummy (left) and radiograph (right) showing nothing inside the wrappings (it was likely intended to be a hawk or falcon mummy).

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CG2015-4-9: Mummy (left) and radiograph (right) showing a young kitten in the upper half of the wrappings, missing its head.

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97-121-8: Mummy (left) and radiograph (right) showing at least 3 snakes inside (scale not included, but this mummy is about the length and width of an iphone).

Animal mummy x-rays

The Artifact Lab has been a busy place lately (thanks in part to a big collections move project), and just last week we got a special delivery of some animal mummies from storage which have not been examined in a long time, and have never been x-rayed.

A cart with animal mummies, some which are still wrapped in tissue paper.

A cart with animal mummies, some which are still wrapped in tissue paper.

While everything has to move out of Egyptian storage, these animal mummies will not be moving offsite – we are finding a temporary home for them elsewhere in the museum. Nonetheless, this move is a chance to examine everything, to upgrade storage mounts, and to carry out minimal conservation treatment as needed.

Project conservator Alexis North photographs an ibis mummy in the Artifact Lab.

Project conservator Alexis North photographs an ibis mummy in the Artifact Lab.

A view of an ibis mummy during treatment to stabilize loose linen wrappings (the silver "kisses" are small weights)

A view of an ibis mummy during treatment to stabilize loose linen wrappings (the silver “kisses” are small weights)

So while we have these mummies in the lab, we thought we’d also take the opportunity to x-ray them using our new(ish) digital x-radiography equipment. There have been stories in the news recently about what x-rays and CT-scans have revealed about animal mummies in other collections and we’re interested in knowing how ours compare.

Alexis arranges an animal mummy on the x-ray digital capture plate below the x-ray tube.

Alexis arranges an animal mummy on the x-ray digital capture plate below the x-ray tube.

We will follow this post with some images of each of the mummies and what the radiographs revealed. Sorry to leave you hanging but I promise it will be worth the wait! Also stay tuned to the museum’s Facebook and Instagram accounts for another mystery mummy quiz!

A closer look at one of our feathered friends

We have an ibis mummy in the lab, which is revealing itself to us in an unusual way.

Unlike most animal mummies in our collection, we can actually see the ibis’ remains – in this case, its feathers! It is unfortunate that the linen wrappings were damaged in the past, but this damage does provide a unique look under the bandages.

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Ibis mummy, 97-121-19, from Thebes, Late Period (ca. 664-332 BCE).

While x-ray radiography revealed that there is indeed an ibis inside (the beak is a dead giveaway), the feathers provide further clues about this bird that was mummified approximately 2500 years ago.

Radiograph taken from the top down. Exposure information: 35kV, 5mA, 6 seconds. Image enhanced with flash! filter.

Radiograph taken from the top down. Exposure information: 35kV, 5mA, 6 seconds. Image enhanced with flash! filter.

When researching ibis mummies, I read again and again about the African Sacred ibis (Threskiornis aethiopicus) being mummified, but there were other types of ibis in Egypt, including the Glossy ibis (Plegadis falcinellus) and the Northern Bald ibis (Geronticus eremita). I don’t know if evidence has been found that these other types of ibis were mummified, but I do know that I shouldn’t immediately assume that this particular ibis mummy contains the remains of an African Sacred ibis.

So, let’s look at the feathers, and what we can learn from them. The feathers that are exposed appear to be contour feathers that may be part of one of the wings. There are a few completely detached feather fragments in this area, so I was able to take a closer look at one small fragment under the microscope.

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Left: ibis feather 7.5X magnification. Right: ibis feather 50X magnification.

The most obvious feature to note, even without a microscope, is the coloration. This feather is white and black. The African Sacred ibis has a very beautiful, distinctive, black and white plumage, so in this case the color alone may be enough to identify species.

If we can’t rely on color, what else can we learn from this feather fragment? Well, we can see that it is part of a pennaceous (rather than plumulaceous, or downy) feather, the parts of which I’ve labeled in the above images. To take an even closer look at these elements, I used our polarizing light microscope and was able to see the tiny hooklets on the barbules, which “zip” the barbules, and therefore the barbs, together.

Ibis feather 100X magnification.

Ibis feather 100X magnification.

The barbules of feathers can be used for identification of species, but usually barbules from plumulaceous feathers are used, as they have a very different and distinct appearance. Unfortunately, I don’t have access to any plumulaceous feathers from this ibis mummy, so this may be as far as I can go at the moment. There are other researchers, both within the field of Egyptology, but mostly in ornithology, who have spent much more time looking at ibis feather structure than I have, and of course there is DNA research, so we may learn more in the future about this ibis mummy and its feathers.

I have a special place in my heart for birds and feathers, since before coming to the Penn Museum, I worked on an extensive project on feather coloration as part of a collaborative research effort between UCLA and the Getty Conservation Institute. Click on the links below to find out more about this work:

A Collaborative Study of California Featherwork

California Featherwork: Considerations for Examination and Preservation

And to learn more about feather structure, start by following this link: The Cornell Lab of Ornithology: All About Birds: Feather Structure