Yeah, welcome back everybody. Today we have another invited talk and it's a great pleasure

to actually announce three guests today. So we have Jana Damboglio, who is a conservator,

researcher and educator, letter locker and artist who specializes in developing freely

accessible resources and treatment techniques to conserve the integrity of material culture

and the secrets they contain. At present, she is a conservator at the Massachusetts Institute

of Technology, Curation and Preservation Services. Then we have Dr. Daniel Smith, who is a lecturer

in early modern English literature at King's College UK, and he is performing award-winning

research which just recently won the John Donne Society Distinguished Publication Award

and the University English Book Prize. Then we have G.R. Davis, who is a professor of

3D X-ray imaging at Queen Mary University of London and lead for imaging sciences in

the Center for Oral Bioengineering, which includes electron microscopy, X-ray imaging

and facial scanning. So it's a great pleasure to have you here. And yeah, today's session

is entitled, Letter Locking, a Global Technology of Communication Security. Yeah, so great

to have you here and the stage is yours.

Thank you. I'm going to share a quick slide very quickly as I introduce what we're going

to do today and then we'll get on to our talks. First of all, thank you so much for your interest

in our research. Thanks so much for having us. Thank you, Andreas, for the invitation.

We're really excited. We've been talking about some of our findings and methods to all sorts

of different groups, art historians, scientists, imaging experts, curators, literary scholars,

historians, and it's always so interesting to talk them through and hear what people

make of them and think about how they could be applied or changed or adapted. So we're

really keen to hear what you make of all of this. What we'll be doing today is three authors

from a recent paper that we published in Nature Communications, Unlocking History through

Automated Virtual Unfolding of Sealed Documents, imaged by X-ray Microtomography. We don't

go for brevity in this group. And so we've got three authors today. We're going to talk

about some different aspects of this paper and then we're going to open it up to questions.

So what we're going to start is Graham Davis is going to talk to you a bit about X-ray

Microtomography, the scanning techniques that we used to X-ray a letter from 1697, which

remains in its unopened state. It's never been opened, but we've been able to read the

contents and we've been able to work out what its internal and external engineering are.

We will then talk a little bit about the algorithm that was used to unfold this, although we're

not algorithm experts. We'll be presenting that part of the research. And then Jan and

I will talk you through letter locking. There'll then be a little pause. If you want to ask

questions of Graham, that would be the time to do it because Graham has stepped in very

kindly at late notice and can't stay for the whole session. So if you have questions about

the X-ray Microtomography, I'm sure he could probably also answer some of the questions

about the algorithm too. And then we'll go on to the second half, which will be the practical

hands-on session. So I'm going to stop sharing now and I'm going to hand it over to Graham.

Thanks very much, Daniel. Let me get my presentation up.

I think that's the one. OK, so what I'm going to show you here is some slides which I've

sort of cobbled together, mostly from an older presentation with a few new ones thrown in

for good measure. And more about the name Eric later. But what I'll do is give a sort

of a little bit of background to where we're coming with this 3D X-ray Microtomography

and what the difference is with the system that we use and how that's been helpful for

looking at the letters. And some examples of the type of algorithms. Now, these aren't

as complex as the algorithms developed by MIT for unfolding these letters, which will

be talked about later. That's way beyond my pay grade. I'm not as smart as Holly Jackson,

the youngest member of the team by any means. But it'll give you an idea of how we deal

with this sort of 3D data. Are we going to move on? Yes, it is. OK, so first of all,

XMT, X-ray Microtomography, it's a bit of a mouthful. Unfortunately, it isn't really