Out with the old, in with the new

There are some new objects to see in the lab!

Just this week, we began returning some of our recently-treated objects to storage and exchanging them for some new stuff, including a painted wooden coffin (this is a photo of the coffin box without the lid – note the elaborate painted decoration on the interior):

coffina falcon coffin and “mummy” (I’m putting “mummy” in quotes here because this mummy looks like it’s a corn mummy, made by wrapping up a mixture of sand, grains, and plant fibers):

falconmummythese pieces of a painted wooden coffin board with two Wedjat eyes:

coffinboardand this ibis mummy, with exposed feathers!

ibismummyThere are some other things too, including some cartonnage and another animal mummy, which we’ll post photos of soon.

As always, these photos really don’t do these objects justice. You’ll have to come check them out in person! And we’re only just starting to examine them, so we’ll definitely post information as we learn more. If you have specific questions about any of these objects, please let us know!

 

Looking inside our falcon mummy

Last Friday, 7 of us from our conservation department took a group of objects from the museum to the GE Inspection Technologies Customer Solutions Center in Lewistown, PA for x-radiography and CT scanning.

Our group gathered around the CT scanner, being operated by Becky Rudolph, GE's North American Radiography Sales Manager for Academia

Our group gathered around the CT scanner, being operated by Becky Rudolph, GE’s North American Radiography Sales Manager for Academia

Now, wait just a second, you might be thinking. Doesn’t Penn have its own x-ray and CT scanning equipment? Why did we have to take these objects all the way to Lewistown for this work? Good questions, and we have a good answer. We just received word that in early 2014, construction will begin on our new conservation labs, which will include a digital x-ray suite. We plan to purchase the x-ray unit from GE, so a visit to their facilities was a chance for us to demo the equipment using some of our own artifacts!

The object I was most eager to image was our falcon mummy. X-ray and CT (computed tomography) scanning technology allow us to “virtually unwrap” this mummy, helping us understand how it was made and what is inside (and as visitors to the lab have heard me say, we can’t assume that there are any falcon remains inside-we can only hope!).

The falcon mummy laying on its storage support on the x-ray plate (within a lead-lined room)

The falcon mummy lying on its storage support on the x-ray plate (within a lead-lined room)

The quickest way to get a peek inside the falcon mummy’s wrappings is by taking an x-ray image. Digital x-ray technology is amazing – with a push of a button, 135 kV (kilovolts, measurement of the voltage), 2.0 mA (millamperes, measurement of the current) and 4 seconds later, we saw this:

falcon xray annotatedHooray! In this first attempt, we could already see that there are bird remains inside. The bright white material concentrated in the center of the mummy wrappings is the skeletal remains. In radiographic images, materials that are denser appear white because they do not allow x-rays to pass through. Materials that are less dense (such as the textile wrappings surrounding the bird bones) appear darker, because the x-rays are penetrating and passing through these materials. We can see in the image above that there are no skeletal remains in the “head” and the “feet” of the falcon mummy – these areas appear to have been sculpted with fabric. The slightly brighter white area near the feet just reflects an overlap of textile in that area.

While we were excited by this image, it immediately prompted more questions. We can see bird bones, but where is the skull? How much of the bird body is present? Are there any clues as to how the body was prepared for mummification? To answer these questions, we turned to the CT scanner.

CT scanning uses x-rays to produce cross-sectional images of an object, which can then be combined to produce three-dimensional views. CT provides a much more detailed look inside objects, and better distinction between different materials.

The CT unit at GE does not look like a medical CT scanner that many people may be familiar with. To scan the falcon, we had to stand the mummy upright in its box, which we then secured to the rotating stage inside the CT chamber with masking tape.

Right: Lynn Grant and I taped the falcon mummy in his box to the stage inside the CT chamber. Left: another view of the falcon mummy's box secured inside the CT chamber.

Left: Lynn Grant and I taped the falcon mummy in its box to the stage inside the CT chamber Right: another view of the falcon mummy’s box secured inside the CT chamber

The CT scanning took a bit longer than 4 seconds, but again, produced much more detailed images. Here is what one of the cross-sections looks like:

falcon cross section annotatedIn this image, the bones are visible as the most radio-opaque materials (so they are bright white). We were also excited to see the feathers, clearly visible as little circles reflecting the cross-section of the feather shafts, which are hollow. The various layers of linen wrapping are also very clear – clear enough to count! But other details are not so immediately clear to us, including the presence of the skull, and exactly how the remains were prepared.

Here is a screen shot from the program we are using to view the CT images, showing 3 different cross-sections, and a basic 3D rendering of a section of the falcon mummy. In this 3D rendering, we can clearly see the falcon’s talons, circled in red!

falcon CT 3 views annotatedWe will need to spend time with the images, and consult other specialists, to better understand what the CT scans have revealed.

image_2

UCLA/Getty graduate intern Alexis North and I puzzle over the CT images of the falcon mummy

We will follow up later with more images and interpretations of the falcon mummy CT scans, plus more about the other objects we were able to examine.

A special thank you to Becky Rudolph and Hank Rowe at GE for spending the day with us, and for their expertise!

 

X-ray excursion

If you stopped by the Artifact Lab this week, you might have noticed that our falcon mummy is no longer on display, and this sign in its place:

falcon signAs indicated on the sign, the falcon has been removed for x-radiography. This mummy has never been x-rayed before, and we’re interested in using this imaging technology to learn how it was made and if there are any falcon remains inside!

Along with the falcon, we’re also going to be x-raying/CT-scanning our (possibly headless) cat mummy, the wooden statue heads, and several other pieces.

We do not have the ability to x-ray and CT-scan objects here in the museum, so we will be taking these selected pieces for a little trip tomorrow. In preparation for their travels, they are securely packed, and ready for this exciting excursion!

The falcon mummy is secured inside its storage support and packed into a larger box for travel.

The falcon mummy is secured inside its storage support and packed into a larger box for travel.

We will update the blog with our findings soon after we return.

 

Wrapping up the cat mummy

Speaking of Abydos, let’s get back to our cat mummy, which was excavated from a cemetery there back in 1901-02. Our summer intern Anna O’Neill will describe how she carried out the conservation treatment on this very fragile object:

Hello again.  You may remember that last time I wrote about this cat mummy, I got a little distracted.  But this time I’d like to focus on the treatment process.  Many of our mummies are in remarkably good condition, with wrappings that are stable and that can withstand handling (albeit with care).  Not so with this cat.

cat mummy 1When plant-based fibers age, the cellulose that gives them structure decays and the fibers become brittle.  Badly aged linen can fall apart at the lightest touch, leaving loose fragments and powder on the surface of the object.  The linen on top of this cat mummy was torn and obscured by dust, but the real problem was underneath.  Prior to treatment, Molly and I carefully turned the mummy a little so we could see below—and quickly (but gently) put it back!  As you can see in the image below, the layers of linen were falling apart and the threads that had criss-crossed the layers were broken and hanging off.

cat mummy 2We decided to wrap the mummy in nylon netting, which would hold everything in place while keeping the surface visible.  This would be a non-invasive, completely reversible process that would allow the mummy to be safely handled and studied.

Before wrapping, I gave the mummy a light surface cleaning with a variable-speed HEPA-filtered vacuum.  Using a nozzle attachment fitted with a screen, I carefully removed the powder on the top of the mummy.  The linen—though torn—was still soft and flexible, like modern fabric.

cat mummy 3Then, I toned the netting to match the color of the mummy using acrylic paint.  Once the paint was dry, I positioned the netting across the top of the mummy and pinned it in place.  The flip was simple but nerve-wracking—we knew from our quick peek earlier that the underside was in bad shape, but we didn’t know to what extent.  With Molly’s help, I turned the mummy over so that all of the powder, torn linen and broken threads were now on top.

cat mummy 4Since the thick layer of compressed linen powder completely obscured the wrappings below, I again vacuumed the mummy, using a screen to filter out the powder while keeping everything else in place.  A vacuum may seem like an odd conservation tool (I got some weird looks as I hoovered the cat), but with the filter over the nozzle and variable suction control, there’s no danger of sucking up the entire object.

cat mummy 5

The underside of the mummy after cleaning. It may not look like much, but it’s better!

With the underside of the cat finally visible, I sewed the netting up the middle using a flat-felled seam.  As the name implies, this created a neat seam with a flat profile.

cat mummy 6

Overall view of the underside of the cat mummy (after treatment)

Overall view of the top of the cat mummy (after treatment)

Overall view of the top of the cat mummy (after treatment)

Now that the linen wrappings are encapsulated, the little cat mummy can be handled and studied, and it can (hopefully) be x-radiographed this fall.  It still may not have its head, but at least it won’t be losing any more of itself any time soon.

 

Losing it and faking it: investigations into our animal mummies

Hello! I’m Anna O’Neill, a summer intern working in the Conservation Department at the Penn Museum. I’m currently studying to get my MSc in Conservation Practice from Cardiff University in Wales. This summer, I’ve been helping Molly in the Artifact Lab a few days a week and she asked me to write a little bit about one of my projects.

The Egyptians often made votive animal mummies—small, mass-produced animal mummies that pilgrims could offer to the gods. Cats were especially popular as they represented Bastet, the cat-headed goddess of protection, fertility and motherhood. The Penn Museum has several cat mummies in their collection. A few are below:

cat mummiesWe recently started working on E16205, a cat mummy from Abydos (seen below in the image on the left). It was excavated in 1901-02 through the Egypt Exploration Fund through financial support of the Penn Museum, and dates to ca. 381-343 BCE. The linen wrappings are in bad shape—loose, torn and powdery—but that is the least of its problems. After a light cleaning, it became clear that something was missing.

overhead and vertebraAs you can see in the image on the upper right, the linen is damaged and there is a bone exposed at one end of the cat mummy. Zooarchaeologist and Penn professor Dr. Kate Moore confirmed that it’s a cervical vertebra visible at the narrower end of the wrappings.

Dr. Kate Moore examines the exposed cat mummy bone

Dr. Kate Moore examines the exposed cat mummy bone

Animal mummies occasionally lose their heads, as the neck is the weakest point of attachment to the body. Back in March, Molly wrote about our falcon mummy’s floppy head.

In the hope that maybe the head had simply been misplaced, we sent an email to Egyptian Section curator Jen Wegner. A few hours later, Jen turned up in the Artifact lab, smiling and toting a small, tissue-wrapped package. Inside was this little beauty:

Cat head 3quarterIt is evident that this head does not match our cat mummy’s body. The colors and weaves of the linen are different, and the head has carefully articulated features while the body is rather haphazardly wrapped. But the main difference is that there doesn’t appear to be any cat parts within the sculpted wrappings! Inside, the mask contains bundles of linen and resin, but no bones that we could see. A quick look at the records for the head showed that it was X-radiographed in the 1980s and contains “no bony skull”. It is a fake—but an ancient one!

Cat head above below

Additional views of the cat mummy head from above (left) and below (right)

Faking mummies, particularly animal mummies, was not uncommon in ancient Egypt. The materials to make a mummy, like myrrh and natron, were costly. Instead of embalming, the expense could go towards elaborate wrapping and detailing. Once the linen was in place, a religious pilgrim wouldn’t know whether or not there was an actual mummy inside. Several other Penn Museum animal mummies were X-radiographed along with the false head, and it turned out that the middle cat mummy in the image at the very top of this post doesn’t contain any skeletal matter, either. A clue is in the shape of its body—it is wide at the top and narrow at the feet, upside-down in comparison to the real cats.

So, were the mummy-makers pulling the, ahem, linen, over devotees’ eyes?  It is unclear whether the pilgrims knew that the votive mummies they offered to the gods were impostors, and nor do we know if it mattered. The qualities represented by the animal sacrificed may have been more important than its physical body. This way, a fake mummy representing the “idea” of a cat was an equally valid gift as the mummy of a real cat.

We’re disappointed that we can’t reunite our cat mummy body with its head, but Molly and I are going to work to stabilize the wrappings so that it can be CT-scanned and studied. In the meantime, it’s been interesting to see which of the Penn Museum’s votive mummies are real and which are (ancient) fakes.

 

Field trip!

Sometimes getting started on a conservation treatment requires getting out of the lab for a bit, so this week, my colleague Julie Lawson and I took a field trip down to Baltimore to visit the Johns Hopkins Archaeological Museum and chat mummy treatments with their Curator/Conservator, Sanchita Balachandran. Sanchita and I connected at the American Institute for Conservation (AIC) annual meeting back in June – I had read about a treatment that she carried out on a human mummy at the museum, and when we realized that we both had animal mummies in our labs as well, we decided we’d get together for a brainstorming session to discuss treatment approaches, materials, and storage options for these fragile objects.

Julie Lawson admires artifacts in one of the cases in the Johns Hopkins Archaeological Museum

Julie Lawson admires artifacts in one of the cases in the Johns Hopkins Archaeological Museum

The Johns Hopkins Archaeological Museum is nestled in the center of the Johns Hopkins Homewood Campus in Baltimore, in a beautifully-renovated building, surrounded by classrooms and light-filled student study spaces. The museum was established in 1882 and since its founding, has been dedicated to inspiring and teaching students at the university.

One of the main features of the museum is the display of archaeological objects from ancient Greece, Rome, Egypt, the Near East, and the ancient Americas, displayed in glass case walls, allowing students, faculty, and visitors to view these pieces and peer into the museum itself.

museum2_compThe museum also displays pieces on loan, including an ancient Egyptian mummy from Goucher College.

Goucher mummyThis was the mummy that I had read about and was curious to learn more about from Sanchita. The Goucher mummy is an adult female mummy from the Ptolemaic Period (305-30 BCE), and I knew some details of the treatment from Sanchita’s article in the Journal of the American Institute for Conservation (JAIC), but this was a great opportunity for me to see this mummy up-close and to ask Sanchita more about how she approached this treatment and the specific materials and techniques she used. Since we are in the middle of working on the treatment of our mummy PUM I here in the Artifact Lab, this conversation was very timely.

Detail of the Stabiltex encapsulating the feet of the Goucher mummy

Detail of the Stabiltex encapsulating the feet of the Goucher mummy

The Goucher mummy has a fascinating history that I won’t get into here, but you can learn more about her in the “Object Stories” section of the museum’s website by following this link. One of the things I was curious to discuss more with Sanchita was her use of Stabiltex, a sheer polyester fabric, to protect fragile areas of the mummy’s wrappings, and the design and construction of the support the mummy is currently resting on in the exhibit. As I said, we’re working on encapsulating PUM I’s outer linen wrappings in a similar way, but using a different type of sheer netting fabric. After discussing techniques with Sanchita and seeing how successful her treatment of the Goucher mummy was, I returned to the Artifact Lab feeling good about our approach to PUM I’s treatment!

Sanchita also pulled out several animal mummies that she is currently working on, including these cuties:

Cat (above) and dog (below) mummies

Cat (above) and dog (below) mummies

We discussed the challenges of dealing with such fragile linen wrappings and our experiences with and use of different adhesives, as well as techniques for encapsulating fragile areas. Sanchita also showed us their handling and storage mounts, which go a long way in protecting these artifacts.

Sanchita lifts an ibis mummy from its storage box using a handling tray

Sanchita lifts an ibis mummy from its storage box using a handling tray

After discussing mummies at length, Sanchita took us back into their storage area, where we had the opportunity to see additional Egyptian artifacts, including several painted wood artifacts with a variety of condition problems. As readers to this blog may know, we have our own fair share of challenging painted wooden artifacts, including Tawahibre’s coffin, so I was eager to see how Sanchita was approaching the treatment of these pieces as well.

Sanchita and Julie in storage

Sanchita and Julie in storage

All in all, it was a fun and productive day! These types of professional exchanges are incredibly valuable, and I’m not only inspired to tackle some treatments and try new things back in the lab, but to make more time in the future to visit other colleagues and collections. A huge thanks to Sanchita for hosting us and for sharing so much about her work at Johns Hopkins.

 

New objects in the Artifact Lab

Starting today, there are three new artifacts on view in the exhibit space here in the Artifact Lab. Those of you who have been keeping up with this blog will recognize these pieces, including:

Our falcon mummy:

falcon in caseTanwa, one of our child mummies:

Tanwa in case

and Nefrina’s cartonnage mummy mask:

nefrina in caseAll of these artifacts are displayed with labels explaining their conservation “story”.

In addition, we have a binder available in the exhibit space that includes the conservation treatment reports and images for each of these artifacts. These reports contain detailed descriptions of the materials and the condition of these artifacts, and of the techniques and materials used to conserve them.

Of course, we also have information about these pieces here on our blog, and later this week we will post more information about the process of conserving Nefrina’s mummy mask.

 

It’s hard work, but with lots of rewards

As I’ve said before on this blog, one of my favorite parts of my job is meeting our visitors on a daily basis. This kind of interaction is really rewarding for me, and I hope that the feeling is mutual for those who do get a chance to stop by the Artifact Lab during open window sessions. So you can imagine how pleased I was to find this in my mailbox yesterday:

quinn envelope_addressremovedAs soon as I saw this, I knew exactly who it was from. Last week I was visited by three brothers, Sean, Aidan, and Quinn – their Granddad brought them to the museum for a day, and after doing his homework, specifically came up to the Artifact Lab for our 11:15 open window session. They had lots of questions for me, and we talked for awhile about our animal mummies. I explained to them that we don’t need to unwrap these mummies to know what’s inside – x-rays show us that this rather nondescript mummy -

ibis mummy

- is definitely an ibis, indicated by the characteristic long curved beak which is clearly visible in x-radiographs taken from 2 different angles:

The ibis' beak, indicated here with red arrows, is seen in x-radiographs taken from two different angles.

The ibis’ beak is indicated here with red arrows

To illustrate this in the lab, we printed out one of these x-ray images along with a little drawing of an ibis, and we keep it next to the mummy for comparison. As soon as the youngest brother, Quinn, saw the picture, he quipped, “I wish I could color that!”. So I immediately handed it over to him and asked him if, when he was done coloring, he could share a photo of it with me to post on the blog. Well, he sure didn’t waste any time – not only did he send me his drawing (signed and everything):

Quinn drawingbut the brothers also included a very sweet, and beautifully illustrated thank you note.

quinn letter togetherWhat wonderful artists, and very thoughtful boys. Answering questions can be hard! But with visitors like this, it doesn’t feel like hard work-it’s just fun. Thank YOU Aidan, Sean, Quinn, and Granddad Dan for visiting me in the Artifact Lab and being the highlight of my day!

 

Bobblehead no more: finishing the falcon mummy treatment

As you’ve seen in one of my latest posts, I have been working on the treatment of our falcon mummy, but of course I saved one of the most challenging parts for last. I couldn’t capture a great photo of this, but one of the biggest condition problems with the falcon is that he had a seriously floppy head. This was caused by tears, breaks and losses of the linen fabric in both the front and the back of the body, just below the neck.

Two detail shots of the falcon mummy before treatment, showing breaks and separation of the textile near the neck

Actually, one of the best images showing this is in our online collections database found by following this link. It is evident that there was nothing supporting the falcon’s head in this photo, allowing it to fall backward.

To stabilize this area, I filled the gaps using Japanese tissue paper and methyl cellulose, the same adhesive I used to repair the textile on the feet of this mummy. Japanese paper is commonly used in conservation for the repair of artifacts and paper-based materials. As the name implies, this is paper made in Japan, usually from kozo fibers, which come from the inner bark of the Kozo, or Paper Mulberry tree.

Gap in back of the falcon’s neck during (left) and after (right) filling and mending with Japanese tissue paper.

In areas where the Japanese tissue paper would be visible, I toned the paper beforehand using Golden acrylic paints. I made most of the fills from the back, which allowed the separated area in the front to join together nicely, requiring little additions in this area.

Two views of the falcon mummy after treatment

Many of the dark-brown dyed linen elements were also very fragile and actively detaching, so I consolidated them using a 2.5% solution of Acryloid B-72 in a 50:50 solution of acetone/ethanol. Finally, I created a storage support for the falcon – even though the head is no longer floppy, this will provide important support under the head to reduce stress in this area and to avoid continued damage or failure of the repair.

Falcon mummy after treatment, with new storage tray

The falcon mummy is now ready for transport over to the hospital later this year for CT scanning. CT scanning will be able to tell us if there is a falcon inside the wrappings, and will also provide important information about how these animal mummies were made. Additionally, the CT images will be an important part of my conservation documentation – I will be able to annotate which materials I added as part of the treatment process, to eliminate confusion over what is original and what is not.

Our falcon mummy will also be going on display later this year – and you can visit him anytime by stopping by the Artifact Lab!

 

Giving our falcon a little love

One of my favorite artifacts in the lab is a falcon mummy, which I described in an earlier post. While he is a fascinating object, this poor little guy hasn’t been able to be exhibited, or even handled very much, because some of his linen wrappings are quite deteriorated, brittle, and breaking apart, causing serious structural issues.

Overall shot of our falcon mummy

Recently, I worked to stabilize the linen wrappings on his feet, which were partially detached, and in some areas, barely hanging on by a few threads.

Side view of the falcon’s “feet” showing the fragile, partially detached linen wrappings

Before carrying out any treatment, I did a little bit of research and carried out some testing to determine what materials I might want to use to repair the textile. I knew that a stitched repair would not be possible, as the linen fibers are far too weak and this would likely cause further damage, so I started investigating different adhesives and support materials to use instead. As part of this process, I consulted with Nancy Love, a local conservator in private practice who specializes in textiles. Nancy recently visited me in the Artifact Lab, and among the other materials I was trying, she suggested that I experiment with nylon bobbinett, a heatset nylon net.

I did some experimentation with it, and I really liked how it behaves, both as a support fabric and as an overlay to protect fragile areas-it drapes well and can be toned easily with dyes or paint. After feeling satisfied with the results of some of my tests, I set out to repair the damaged linen over the falcon’s feet.

I started by toning the bobbinett with Golden acrylic paint. Then I backed the fabric that was dangling off the back of the foot with the toned bobbinett lightly coated with 10% methylcellulose in water. I then used the bobbinett support fabric to raise the partially detached fabric up into place, secured temporarily with pins.

After positioning the linen, I covered the entire back of the foot area with another piece of toned nylon bobbinett.

The back of the foot area with an overlay of the toned nylon bobbinett, after treatment

Finally, I tacked down the strip of linen over the top of the feet, which was also partially detached but otherwise fairly stable, using small beads of methylcellulose. Reattaching the linen over this area also hid the edge of the nylon bobbinett overlay.

View of the front of the foot wrappings, after treatment

I’m pleased with the results, and I can now breathe a sigh of relief that we’re not going to lose any more of the linen from this area. My next task will be to address the falcon’s partially detached head/neck area. Hang in there, little guy!