The crocodile mummy is one of the most amazing things in our collection.
It is the largest mummy that The British Museum owns
and it...well we haven't seen it on display for over 75 years.
It arrived in the museum in 1895
it was excavated at a site called Kom Ombo,
which is located about 50 kilometres north of Aswan
in Upper Egypt.
It was excavated by Jacques de Morgan
who was the Director General of the Egyptian Antiquities Service at the time.
My name is Barbara Wills
and I work in the department of Conservation,
Conservation and Sceintific Research at The British Museum.
I have worked here for many years now
and over those years I've had an opportunity to specialise
and one of the things, one of the areas that I specialise in have been the care of mummies,
animal and human.
When the idea for the crocodile exhibition came up
I felt it was a wonderful idea and I was really delighted
that the crocodile came my way
because it's a rare and wonderful experience
to get an opportunity to work on a 12 foot,
4 metre, crocodile.
It's a fabulous piece,
it's absolutely one of the most amazing, amazing artefacts.
It it over almost 4 metres long
and it consists of a large adult crocodile,
and on its back there are a series of
small mummified hatchling crocodiles.
They've been just sat on the back,
basically imitating what you see in nature.
As part of preparation for the Room 3 show
we decided we'd do a CT scan
of the crocodile.
We were really lucky,
we found a CT scanner in the diagnostic imaging unit
of the Royal Veterinary College, here in London.
They were generous enough to allow us to come and
scan this crocodile and it was a fantastic experience.
The thing with CT scanning is that it allows us to investigate
in a non-invasive way.
It really told us an awful lot about the mummification
and the procedures with the animal itself.
The lower part of the torso is still intact
but the upper part of the torso, they've filled with linen packing
but in the CT scans now we can see the stones in its stomach,
the gastrolifts that were used to help it digest its meals
and maybe for ballast as well.
We could see the remains of its last meal
and there were also three very small unidentified metal objects,
and we still don't know what they are.
I don't know if we'll ever find out.
I saw the crocodile, I assessed him or her.
When I say assessed, this means I look at it from the
point of view of how stable is it? How resilient is it?
What must I do so that it can travel safely to and from CT scanning,
it can travel safely to go on display, it can be on display
and then go back into storage
and beyond because if I am going to work on it as a conservator
I would also want to ensure that it is stable for the next decade, 2 decades, 5 decades, 10 decades.
I am looking as far ahead as it's possible for me to look ahead
and so there's a degree of ongoing care with the crocodile.
I note those areas that are unstable, that are cracked,
that are possibly going to drop off, dislocate, delaminate, become fryable, shatter.
All those areas, that's what I'm looking for and I intervene to secure them
prior to the CT scan.
There are some very straight forward techniques
and there are some more complex techniques
but essentially I did the more straight forward techniques with this,
which was to encapsulate it and bind it in such a way
that when it travelled, nothing would fall off
and there were one or two areas where I could see a crack
or something was about to come off and I was able
to insert a paste of stable Japanese tissue paper
along with a really stable adhesive we use.
You can use this to insert in to cracks,
to put underneath areas that are delaminating - that are coming apart
and then you carefully weight it in place,
it dries, it's going to stay.
So that careful packing, along with the museum assistants
enable the crocodile to travel safely for the scanning.
In our records, somebody but we don't know who,
suggested that there might actually be a series of crocodiles,
as in a large crocodile, a slightly smaller crocodile on its back
and then the series of hatchlings,
but we were able to discover with the CT scanning
that clearly there was only one large, adult crocodile
and the hatchlings on its back.
It was a bit of a surprise because we had to come back and say
'Oh it looks as though we've lost an object'
but in fact it really told us an awful lot about the mummification
and the procedures with the animal itself.
Before any object goes on display
a conservator needs to check it out to make sure that it says
its consolidated, its safe to be displayed and there isn't going to be any damage incurred to the object
during the course of its exhibition.
The next phase is me setting aside a period of time
devoted almost exclusively to the care of the crocodile.
Essentially I started from the snout and I worked my way
down to the tail.
This involved firstly removing of the dust because
over the period of a century or more dust accumulates,
and not only is dust visually unnecessary and unpleasant but it obscures the detail.
It's also potentially damaging, quite often the dust
is carbon rich and under high, humid conditions that might actually
begin to damage some of the surface.
So there's a lot to be said for getting rid of dust, other than the aesthetic.
We've got a whole menu of different dust removal techniques,
but mine was a museum vacuum cleaner.
I could adapt the museum vacuum cleaner to take a plastic pipette
that I had modified the end of so you've got a very,
very fine point of suction.
That was great because it I could get into the nooks and crannies and I could also
pick out gently anything that was lost in the nooks and crannies
that might have belonged to the surface of the crocodile.
So some things I was able to pick out and think 'I know where that goes'
and I could stick it back.
This removes a certain amount of dust
but because the crocodile has such a wonderful
chocolatey, toffee-like shiny surface and I wanted that
to be apparent to the visitors.
I was able to lift off the dust using another dry cleaning technique
so, essentially it's a piece of soft rubber called groomstick
and I roll it over the surface and it picks up the dust,
and it's a satisfying job to do.
Often as I clean I will leave a marker to say 'This is the bit I want to come back to, here I must secure this'
and this is the more subtle technique where by you get
the adhesive flows in and underneath the bitumin surface of the crocodile.
This is quite, it's reasonabley sophisticated, you have to flood the area first
with white spirits, then you take your medium for consolidation
and with a fine pointed brush, allow it to drop into your crack
and because you flooded it with white spirits the adhesive flows in
follows the trajectory of the crack, so the white spirits
allows it to penetrate those vulnerable areas and the
other job it does is that it stops the adhesive evaporating
back up to the surface. So it also forms a kind of barrier layer,
so it dries gently and it dries in those areas and sticks together
those pieces that you want stuck together.
So a very pleasing technique.
We also use science to help inform our conservation processes.
So we used SEM scanning to figure out what sort of
botanical, material and linens were associated with the mummification processes.
So today we're going to use this piece of equipment,
which is a Secondary Electron Microscope, or we shorten it to SEM
to look at the samples that we took from the crocodile mummy.
So, we have four different samples to look at.
So we took samples from the external textile covering the mummy,
as well as the textile that's also inside the crocodiles mouth
and then we also have samples of the reeds and the string that was attaching the baby crocodiles
to the back of the mummy.
So what we're doing is, we're using this microscope to
take images, which will help us identify what the fibres in
all the textile materials are.
So it works sort of similar in a way to how a camera would work,
except instead of using light, like a camera would,
we're using a beam of electrons.
And where the image is the interaction of the electrons with the sample.
So the first thing we have to do is we need to mount the sample
Gently stick the sample down onto the surface
and just lightly press it down to make sure it's stuck but we don't want to
squish it too much because we'll destroy some of the structure of the fibres.
The next step is to attach the sample to the base plate,
which goes into the machine and it sets the working distance
that we'll use when we're looking at the sample.
Then we just measure the height to make sure we know what distance our sample is
so we won't get too close to the electron beam when we put it inside the chamber.
It slides in and then locks in place and then we can close up the chamber again.
So we've taken all the air out of the chamber, so now we
can turn on the electron beam.
Here's the first glimpse of the sample.
What we would generally do now is we would just
search around the sample, looking for areas that will help us find the identifying features
for this particular sample.
Actually, what's nice is already here we can see
these dislocations, they sort of look at little bit like a knee joint
and that is indicative of flax.
Then all this other stuff that you can see on the side
is from the resin material that's covering the mummy crocodile,
so that's all on this sample too.
The fibres are splitting a lot, which indicates that its quite a brittle material
which you would expect from it being aged and old.
So we would then just look around the rest of the sample,
looking for other features - there are more identifying features
for flax but obviously that can take a while, you zoom in and out a lot as you move around.
So of course one of the important questions to ask
is what is the resin?
The curator was able to get Caroline Cartwright, the scientist
to come and do analysis on the resin.
The crocodile is covered with a very thick resin
we analysed the resin and it's made from conifer and beeswax
we had thought it was from bitumen,
so this came as a bit of a surprise, but it was able to inform our conservation processes
This is in essence a baby crocodile, not long after it
hatched out of the egg.
What it appears to be is that after the mummification, these hatchling crocodiles were mummified
and prepared. Placed within their sticks, bound on
they themselves were covered with the resin.
Certainly there was a point at which blobs of resin were applied
and the mummified hatchlings was adhered.
This was another journey of discovery,
was to work ones way gently down the back of the crocodile
and as you do, you find the mummified infant crocodiles
some very evident and some not so evident.
What you can see is actually the place where they were
because you can see it's broken off, or there's a fragment of infant crocodile,
or there's a little bit of reed.
So I was able to count the baby crocodiles from one end to another
I came to a number around about 30, I think about 30 had been on the back.
Although now you can see maybe seven or eight clearly.
You've got to come and see this exhibition because it's really cool!
The full length crocodile is juxtaposed against this scan,
so you can actually see the object, you can then see the scan and find out what's inside it at the same time
and you can learn a little bit about the history of the sacred animals.
Basically we're exploring how the Ancient Egyptians treated their sacred animals,
both in life and in death.
With an examination of the mummification processes, but also discovering what its last meal
was and seeing how, through textual information and representations, what they looked at
and what they thought of the crocodile, and how they reveared this very frightening, dangerous animal,
who they thought of as a God.