The National Archives’ role in this project was to stabilize the document and make the
Magna Carta look as clear and readable as it could.
But at the same time we had to design an encasement so that the parchment could be sealed up in
inert gas to prevent oxidation and make it last as long as possible.
Centuries.
Many, many centuries.
The National Institute of Standards and Technology, which is better known as NIST, is a research
laboratory which is part of the Department of Commerce.
A lot of our experiments here at NIST go on in controlled atmospheres, which is basically
what we’re putting inside the encasement, is a controlled atmosphere.
Basically we start out with a three-dimensional model that is created in computer-aided design
software.
We take that three dimensional model into another program that takes tool paths and
we can actually take that model right into the machine.
We started out with a six-inch block of aluminum and machined 90-percent of it away.
That gives us the opportunity to make this with as few joints or spots where there could
be leaks.
I’ll start out with a bigger tool to rough it and then the corners, the radius will be
big and I’ll work my way to a smaller tool to get it to a point.
We’re machining out these pockets for weight reduction on this frame.
I’ve got to take caution to make sure that everything’s going right.
Shall, you want to do the document and I’ll do the seal?
Mm hmm.
So there was that day when the platform came in.
We had all been holding our breath, waiting to see.
Would it fit just the way we wanted it to, which was without any strain at all?
We took a digital scan of the document without ever having the document in possession at
NIST and we were able to transform that scan into a shape to cut the platform exactly to
match it.
I think we all agree that that’s something that we’d like to improve, the fit.
I think we should probably just take that, offset this whole piece by 3 millimeters.
Jay Brandenburg took it back to NIST and when it came back it was just fabulous.
It was a fabulous fit.
When you need to be able to move this encasement that’s where a cart comes in.
The cart was a unique design, to provide a platform for display.
It had to be able to raise and lower the encasement when it’s assembled at a display angle.
It had to be able to move very easily.
It had to be able to be raised and lowered very easily.
Well, it’s important to have a barrier between the document and the platform, which is metal.
And so what we have is a specially-designed paper.
We cut it out to very carefully follow the outline of the document.
Because the paper is very white and the parchment is somewhat translucent it actually brightens
up the appearance of the document.
The mounting system that we use for Magna Carta looks almost like a C-clamp and we screw
it into the platform and then what it does is it holds in place a little mylar tab that
we made that’s just rounded.
Wow.
So it’s there.
It’s not moving.
OK.
It’s perfect, perfect.
We had to come up with a way to determine whether or not what was built was actually
leak tight, and then assemble it.
And then right there.
We then put in the seals, the O-rings.
The conservators are responsible for putting the document onto the platform and putting
it in place.
And lay, put the glass on top of this.
And we then put a frame down on top of the glass that is bolted down to exert the sealing
force.
That sounded pretty good.
Good to me.
It now has the document in there and it is filled with air.
So we need to get the air out.
And we do this by flushing it with high-purity argon which is completely chemically inert.
The gas has to be humidified to a level that is consistent with the environment that the
document has been in before.
Purge gas or the flush gas goes in one side of the encasement, passes through the encasement
and exits out the other side.
And when it does it takes the ambient gas with it.
We actually reduce the residual oxygen level in the encasement down to the part-per-million
level.
The museum world as opposed to our world is entirely different.
It’s almost like night and day.
We really learned to appreciate the differences and the uniqueness of each other’s environment.
The thing that makes me so proud of being part of this is the fact you can bring together
two federal agencies, the expertise, the knowledge, the skills and really do something tremendous.