Ptah-Sokar-Osiris and Treating Painted Surfaces

Julia Commander is a third-year graduate student in the Winterthur/University of Delaware Program in Art Conservation. She is currently completing a curriculum internship at the Penn Museum.

As a conservation intern working in the Artifact Lab, I was able to go shopping through shelves of Egyptian objects and scope out interesting treatment projects. A painted wood statue, depicting the composite god Ptah-Sokar-Osiris, immediately caught my eye. The figure has intricate painted designs decorating the mummiform figure and its base, as well as gilded details in the face and headdress.

Ptah Sokar Osiris Statue, L-55-29A-C

L-55-29C, detail of paint and gilding

High-status burials in 19th dynasty Egypt often included this type of mummiform statue. Comparable examples of the popular object type exist in collections worldwide, such as the British Museum and the Metropolitan Museum of Art. Common characteristics include carved wood, a preparatory gesso layer, polychrome design, and in some cases, a coating of varnish. Ptah-Sokar-Osiris statues also frequently feature small compartments carved into the wood figure or base. These cavities could contain small papyrus scrolls or textile wrappings. While examining the object with this in mind, I noticed a faint rectangular shape on the reverse of the figure’s head.

X-radiography, a non-destructive imaging technique that helps clarify construction details, was perfectly suited for the question of the compartment. Without disturbing the delicate painted surface, we were able to observe that a rectangular cavity is in fact cut into the head of the figure. Although the cavity appears to be empty, this interesting construction detail is consistent with similar Ptah-Sokar-Osiris figures.

L-55-29A detail (left) and X-radiograph (right). Image captured from 55 kV, 2 mA, and 6 second exposure.

The statue has several condition issues, such as actively flaking paint and significant darkening over the front surface. Additionally, the figure is unable to stand upright in the base, and the components do not fit together securely. Upcoming treatment aims to address these issues, and I will be searching for the right approach to cleaning and consolidation. The complex surface made of wood, gesso, and paint will require detailed testing to find appropriate solutions.

To further investigate painted surfaces and possible coatings, I used multispectral imaging (MSI), which incorporates multiple light sources to reveal details that cannot be seen in visible light. Interesting findings included the presence of Egyptian blue in the figure’s wig and broad collar, as well as the headdress. This pigment shows up in visible-induced infrared luminescence and is easily distinguishable from surrounding pigments.

Detail of multispectral imaging, highlighting Egyptian blue pigment. Normal light (top), visible-induced infrared luminescence (center) with Egyptian blue shown in white, and false color image (bottom) with Egyptian blue shown in red.

Learning more about the object’s structure and surface will help inform treatment decisions about this complex figure. Check back to see what else we learn and how treatment will proceed!

Animal mummies: contents revealed part II

This is a follow-up to my last blogpost, where I posted some side-by-side images of animal mummies and their x-rays. In this post I’m going to explain what we think we’re seeing in the radiographs.

Let’s start with one of the easiest ones:

50-17-1: mummy paired with radiograph

50-17-1: mummy paired with radiograph

This one is really easy. While the mummy is made to look like a cat, we can clearly see that there are no cat remains, or any remains, inside. All we see inside are very small straight pins, which were pushed into the linen wrappings in 1980 to keep them from unraveling. We know this happened in 1980 because it is noted in an old conservation report. A good example of an ancient “fake”!

The next one is also fairly easy to interpret.

ibismummygif

E12438: mummy from the side, paired with radiograph

We thought this was an ibis mummy, and sure enough, we see an entire ibis inside the wrappings. The GIF above highlights the distinctive skull and beak of the ibis in red.

You could say that the next one, which appears to be a crocodile mummy, has a couple extra special surprises inside:

crocgif

E17631: mummy from above, paired with radiograph

There are 3 baby crocodiles under the wrappings! The GIF above highlights the 3 skulls in red.

Next we have what appears to be a falcon mummy, but what we see inside is harder to interpret:

falcongif

E12441: mummy paired with radiograph

Upon close inspection, we can see 2 separate, and very small birds inside. In the GIF above, the red outlines the skulls and beaks and the blue outlines the bodies. We don’t think that these birds are falcons, or even birds of prey at all. They look much more like doves or pigeons (based on examination of comparative specimens with zooarchaeologist Dr. Kate Moore). It’s possible that this mummy was never meant to represent a falcon at all – the jury is still out on this one.

Lastly, we have the tiniest mummy of the bunch:

shrewgif

E12435: mummy from the side, paired with radiograph

There is an animal inside, and it looks like its body is upside-down. It is very difficult to make out, but we can see its front teeth and its long tail. This one definitely called for the expertise of Dr. Moore, who brought up some comparative specimens from her collection. Ultimately, it was the teeth that convinced her that what we see inside this little mummy is a shrew.

Dr. Moore holding a tiny shrew skull

Dr. Moore holding a tiny shrew skull

To the ancient Egyptians, the shrew represented the nocturnal side of Horus. Here is a link to an image of a similar shrew mummy in the collection at the Brooklyn Museum.

Our fun with animal mummies never ends! For more information about where these mummies came from, check our their catalog records in our Collections Database:

50-17-1: Cat mummy

E17631: Crocodile mummy

E12441: Falcon mummy

E12438: Ibis mummy

E12435: Shrew mummy

Animal mummies: contents revealed part I

We x-rayed several animal mummies last week.

Here we are checking in on our patient. Isn't this little kitty mummy so cute, just lying there on the x-ray plate?

Here we are checking in on our patient. Isn’t this little kitty mummy so cute, just lying there on the x-ray plate?

Most of these mummies were on display in the Secrets and Science gallery until 2 weeks ago and several of them are going back on display soon. So now is our time to learn as much about them as possible!

We teamed up with Dr. Kate Moore, CAAM teaching specialist and zooarchaeologist, to see if we can figure out what is under the wrappings of these little (and a couple really little) mummies.

I’m going to divide the information about this project into 2 different posts. For this first post, I’m going to show side-by-side images of the some of the mummies and their x-rays, and welcome readers to make some guesses as to what is inside. I’ll follow this post by providing some information on what we think we are seeing, and some outstanding questions we still have.

E12438: mummy from the side, paired with radiograph

E12438: mummy from the side, paired with radiograph

E17631: mummy from above, paired with radiograph

E17631: mummy from above, paired with radiograph

E12441: mummy paired with radiograph

E12441: mummy paired with radiograph

E12435: mummy from the side, paired with radiograph

E12435: mummy from the side, paired with radiograph

50-17-1: mummy paired with radiograph

50-17-1: mummy paired with radiograph

You can find out more information about these little mummies by searching our Collections Database online (and also by looking at our Current in the Lab tab on this blog). We’ll blog about our interpretations soon.

Conservator Alexis North viewing a radiograph down in our x-ray room

Conservator Alexis North viewing a radiograph in our x-ray room

Vampire mummy?!?

In the last couple days we found out a bit more about one of the animal mummies we recently x-rayed.

The clue is related to one of the cat mummies, which came into the lab looking like this:

CG2015-4-9 in (not original) coffin

CG2015-4-9: cat mummy in (not original) coffin

First of all, you might be asking yourselves, how did we keep this amazing detail from you before? This mummy was previously stored in an creepy/wonderful vampire coffin with a glass cover (not original to the mummy). It was sealed inside the coffin, presumably to make it more attractive (?) for collection/sale. In order to get a better look at the mummy and carry out treatment, conservator Alexis North had to remove it from the coffin. Once it was out , we could see that the head had been intentionally cut off.

CG2015-4-9, view from top showing where head was cut off and exposing bones inside

CG2015-4-9, view from top showing where head was cut off and exposing bones inside

Inside the coffin, Alexis found some bits of bones, including this:

Portion of a maxilla (upper jaw), including teeth, 10X magnification.

Portion of a maxilla (upper jaw), including teeth, 10X magnification

This is a portion of the maxilla (upper jaw) of a cat with some linen and even some fur still attached! Based on it’s size and the fact that the incisor is not fully erupted, we* estimate that this belonged to a kitten that was only a few weeks old when it died. The size of the bones corresponds well with the size of the kitten’s body we saw in the x-radiograph. Here’s that image again, showing how small the kitten is in relation to the size of the mummy:

The radiograph shows that there is only a tiny kitten under the wrappings of this cat mummy.

Left: Cat mummy. Right: Radiograph of the cat mummy, which shows that there is only a tiny kitten under the wrappings.

There are other bits of the skull that we found inside the coffin too. We’re not sure when the head was removed, but afraid that the head may have been cut off to fit the mummy into the vampire coffin. We’ve made a new box for the mummy, one that is both more appropriate for this object and for the museum environment, and that will certainly be more protective.

Cat mummy in a new storage enclosure

Cat mummy in a new storage enclosure

*Special thanks to Dr. Kate Moore for her expertise and time!

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.

ibismummy4

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).

kittenmummy

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

snakemummies

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!

X-raying fragments of a painted wooden coffin

I recently completed the treatment of these coffin board fragments.

E12617A-C, boards from a painted wooden coffin, before treatment

E12617A-C, boards from a painted wooden coffin, before treatment

In addition to the cleaning, which I blogged about before, the treatment involved stabilization of loose and powdery gesso and paint, filling losses where needed for structural support, and x-radiography, multispectral imaging, and portable X-ray fluorescence (pXRF) analysis. It has also enabled a translation of the text. I’m going to write a few shorter posts to highlight the different components of this project, starting with the x-radiography.

During my initial examination of the boards, I could see that the boards represent just a portion of the front, head end of the coffin. The rest of this side of the coffin would have continued much further to the left, but at some point these pieces were cut down and finished off on the left side to a smooth edge. This is most evident when you look at the hieroglyphic text, which obviously should continue to the left.

I could see that these 3 boards were originally joined with wooden dowels, because there are wooden dowels protruding from the join edges. I also noted some large cracks in the painted surface of the largest (center) piece in the image above, which led me to realize that this central piece was made of more than 1 piece of wood. I turned to x-radiography to get a better understanding of what is going on below the surface.

Here is a composite image showing the radiographs of the 3 boards:

E12617A-C x-ray image

E12617A-C x-ray image

The dowels joining the 3 pieces together are very clear in the x-ray image above. There are some darker (almost black) areas, which represent the holes that were drilled out for inserting the dowels. The denser (whiter) areas within those voids are the wooden dowels themselves. I’ve outlined these areas in green in the image below.

E12617xraymapped-1The x-ray image also helps clarify how the center piece is constructed, with 3 pieces of wood, which I’ve outlined in red above. Where those 3 pieces of wood join correspond directly with the cracks observed in the painted surface on the exterior.

Also visible in the x-ray image are two small nails driven into the lower edge of the bottom board. These nails are historic additions, likely added at the time when the boards were cut down and modified, although their purpose is unknown.

In my next post, I’ll focus on what cleaning, pXRF, and multispectral imaging has revealed about the painted surface, and I’ll include some after-treatment images.

 

A tiny mystery mummy

Yesterday we x-rayed mummies of 2 extremes: a full-sized human mummy (Nespekashuti), and a tiny mystery mummy:

mystery mummy

This tiny mummy is about 2″ wide and 5″ long, and easily fits into one of my hands.

We already had the x-ray tube warmed up for capturing images of Nespekashuti, so we figured we’d zap this little mummy while we were at it, to find out what is underneath those wrappings. We had lots of guesses, but ultimately, none of us guessed correctly.

Here is one of the x-ray images:

An x-ray image of our tiny mystery mummy

An x-ray image of our tiny mystery mummy

We had 3 conservators in the room when this image popped up on the computer screen, and we were immediately puzzled. Bird? Definitely not. Crocodile? No. Mouse? Nope. Cat? Again, a no. Could it be a…dog? We knew that the 3 of us non-experts couldn’t say anything with any certainly, so we called in the big guns…in the form of zooarchaeologist Dr. Kate Moore, who has helped us with some of our other animal mummies in the past.

Dr. Moore spent some time looking at the images, and then looking at some x-ray images of immature dogs (puppies!). She was troubled by a few things, including the fact that we can’t see any teeth and that the animal appears to have only 1 leg, also the length of the spine and front paws/feet, but ultimately concluded, based on the x-ray images that we captured, that this is indeed a puppy, who died right around the time it was born.

Based on its size, I don’t think any of us expected this tiny mummy to contain a dog, but it’s not surprising that we would have a dog mummy in our collection, since millions have been found in Egypt, notably in the Dog Catacombs of Saqqara. And this isn’t the only puppy mummy in our collection – if you visit the museum, you can see Hapi-puppy on exhibit, displayed at the feet of his owner, Hapi-men, both of which have been CT-scanned. A CT-scan of our newly-discovered puppy mummy would provide greater detail and a better understanding of this tiny animal, and would help make a more certain identification. We’ll be sure to update the blog with any new findings if we are able to do some more imaging.

 

Conservation at the Penn Museum: the next generation

Update – this post contains outdated language. We no longer use the term “mummy” and instead use “mummified human individuals” to refer to Ancient Egyptian people whose bodies were preserved for the afterlife. To read more about this decision, follow this link

Our department temporarily gained a member last week, when aspiring conservator Jessica Schwartz returned to spend an afternoon with us.

Conservator Tessa de Alarcon shows Jessica an RTI (reflectance transformation imaging) file of a seal impression from Ur.

Conservator Tessa de Alarcon shows Jessica an RTI (reflectance transformation imaging) file of a fragment of a jar stopper from Ur. The seal impression is so worn, and RTI revealed that it actually has 2 different impressions on it.

Jessie, a 6th-grader from Atlanta, has been interested in archaeology for as long as she can remember, but after seeing us working In the Artifact Lab two summers ago, she redirected her energy to pursuing archaeological conservation. There aren’t many opportunities for 12-year olds to gain experience in conservation, so we thought that if she spent some time with us, she’d get a taste of what we do on a day-to-day basis.

The first time she worked with us, last summer, we spent some time looking at our Predynastic male mummy  using our microscopes to identify materials, and making scarab amulet impressions, and she wrote about all of this on the blog, which you can find by following this link.

Last week she came for a return visit (her family was here for the opening of our new exhibition, Beneath the Surface: Life, Death, & Gold in Ancient Panama) and she kept pace with all of the activities of the afternoon, including discussing my ongoing treatment of Pinahsi, a New Kingdom mummy (she had a good eye for picking out where I had repaired the textile shroud!) and reviewing radiographs of some of our animal mummies.

Jar of dirty cotton swab tips

Jar of dirty cotton swab tips

One of the first questions Jessica asked me when she came into the lab was, “what is that container full of little bits of cotton for?”. I’m so glad she asked (it’s a cotton swab disposal jar), because it gave me the idea to teach her one of the most important skills for a conservator to have – rolling your own cotton swab! We make our own swabs for cleaning objects because it allows us to have more control over the size and shape of the swab and the amount of cotton, and it’s also a lot cheaper. Jessica was so pleased with learning this new technique – I told her it would take her far!

Jessie with a successfully-rolled swab

Jessie with a successfully-rolled swab

After working in the Artifact Lab for a bit, we went downstairs to our new digital x-ray lab* to review some animal mummy x-radiographs. I x-rayed the animal mummies just before Jessie’s visit, so this was an opportunity for us to learn from the radiographs together. (*We are super excited about our new digital x-radiography equipment and we are just starting to use it to examine objects in our collection. I have been meaning to write a post just about the equipment and some of the things it has already allowed us to do, so look for this in the near future.)

One of the mummies we x-rayed was this ibis mummy, which our graduate intern
Alexis North treated over the summer. As far as we know, this mummy had never been x-rayed before, so we really had no idea what the radiograph would reveal. Here are the 2 views we captured:

X-ray image taken from the top down. Exposure information: 30kV, 1mA, 6 seconds

X-radiograph taken from the top down. Exposure information: 30kV, 1mA, 6 seconds. Image enhanced with flash! filter.

X-ray image taken from the side. Exposure information: 35 kV, 1mA, 6 seconds

X-radiograph taken from the side. Exposure information: 35 kV, 1mA, 6 seconds. Image enhanced with flash! filter.

Both views clearly show that there are bird remains inside, and the side view shows the characteristic long, curved beak of the ibis really well. The radiographs also show the textile wrappings and even the materials in the storage support! But focusing on the bird remains, they seemed a little…sparse. So we consulted with the museum’s zooarchaeologist and teaching specialist Dr. Kate Moore. She brought us into her lab and showed us a complete heron skeleton (she doesn’t have an ibis skeleton, but a heron is very comparable in terms of size and the shape of the bones).

TessaJessieKate

Dr. Kate Moore (far right) shows Tessa and Jessica a heron skeleton

Here is the complete skeleton, which Kate piled up on the table so that we could get a sense of how much volume those bones take up. After seeing these bones, we took another look at the x-radiograph, and realized that our ibis mummy only contained about half the bones of a complete skeleton (for starters, the pelvis is missing completely).

Heron bones

Heron bones with sharpie marker used for scale.

As you can see, we had a full afternoon, and we learned a lot together. Jessie had to fly back to Atlanta today to turn her attention back to her current full-time job, being a sixth grader, but we look forward to her next visit. While college, and conservation graduate school, are a bit far off in the future, we can already see that if Jessie ultimately decides to pursue conservation, she’s going to excel!

X-rays and the statues eyes

left eyeIn a previous post, we told you that the two wooden heads were going to be X-rayed and CT-scanned, alongside with some other artifacts from the Lab.

In this post we will deal with what we learned about the wooden heads’ eyes from the X-radiographs only.

A lot of our readers will probably know what X-rays are, for they may have experienced them in a hospital. X-rays are also successfully used in Art and Archaeology (for a general overview and some examples, see SCHREINER et al, “X-rays in Art and Archaeology – An overview). The principle of the X-ray is to expose a material to x-ray energy of a particular wavelength. According to the molecular weight of the material, the x-rays will, or won’t, be allowed to go completely through it. The energy that does penetrate passes through to a detector.

In digital radiography, the data is then processed by a computer and, eventually, we obtain a picture where dense (high molecular weight) materials appear white and lighter ones (low molecular weight) are black.

X-ray photograph of E17911

X-ray photograph of E17911 – We can see a lot of termite tunnels and the big hole inside the head, on the right-hand side, and the shining eyes.

E17911, in profile - This picture allows us to see more clearly the structure of the eyes.

E17911, in profile – This picture allows us to see more clearly the structure of the eyes.

New Picture (2)

E17910 – Also helpful about the inserting of the eyes.

In these radiographs, we clearly see the structure of the inlaid eyes. In fact, those eyes are quite similar to those studied at the Louvre Museum on Kay’s statue (ZIEGLER, Les statues égyptiennes de l’Ancien Empire, Musée du Louvre, 1997, p.256). This statue is from the Vth Dynasty, not so far in time from our heads.

Eventually, we can conclude that the eyes are made of a metallic sheet soldered in the back, which is flat. It is shell-shaped and the hippo ivory is inserted inside. Then the black pupils (made of obsidian?) are placed in the ivory, maintained inside by an adhesive (resin ? plaster ?).

New Picture (3)

X-ray radiography photograph of Kay’s statue eyes (from ZIEGLER, 1997, p.256).

Structure of Kay's eyes (from ZIEGLER, 1997, p.259); the back of the metallic part is flat and the edges were folded so as to form the eyelids.

Structure of Kay’s eyes (from ZIEGLER, 1997, p.259); the back of the metallic part is flat and the edges were folded so as to form the eyelids.

Structure of Kay's eyes and identification of the materials we have on Adu's eyes (from ZIEGLER, 1997, p.259)

Structure of Kay’s eyes and identification of the materials we have on Adu’s eyes (from ZIEGLER, 1997, p.259)

 

 

 

 

 

 

 

 

 

 

Fortunately, the Penn Museum has some inlaid eyes in storage, allowing us to figure out more clearly what we have on the heads.

New Picture (7)

The eye n.E6789B – Limestone and obsidian.

 

Back of the eye n.E12905A - Copper alloy.

Back of the eye n.E12905A – Copper alloy.

 

 

 

 

 

 

 

 

 

 

 

Again, fortunately for us (yes, fortunately!), the Louvre Museum has a very interesting statue, also from the Old Kingdom, with missing eyes. This statue of a nobleman named Tcheti informs us on how the inlaid eyes were inserted into the wood.

Tcheti statue, Louvre Museum n.E11566 - Detail of the missing eyes.

Tcheti statue, Louvre Museum n.E11566 – Detail of the missing eyes.

We can see that a hole was cut in the wood, fitting the eyes’ size. We can suppose that an adhesive was used to prevent the eyes from falling off the statue.

As you can see, a conservation intervention, apart from treating the objects, can also allow us to study them more closely and to know them better.

We will talk about the CT-scan in a next post and, in the meantime, you’re more than welcome to visit us at the Lab or to post a comment below !