This was a landmark paper and we there postulated that the... that why there was a virus which had 60 units for example, and polio starts out with 60 units but later on the proteins get cut up into smaller pieces after assembly, and there are others like that. So we postulated that there were... had to be multiples of 60 and Caspar and I enumerated all the possible ways, putting together multiples of 60 units together to build different shells. And it turns out not every multiple of 60 is possible, so we developed the rules for that. And...  but the... since then, all the spherical virus structures and indeed all cage structures do obey one of these principles; but, it turns out that the way they are realised is different, it's their exceptions. And Don Caspar and I parted company later on about... later on when he began to say there were no rules. I won't go into that but it turns out really that... So this spherical virus... this structure... structure of the spherical viruses was quite a triumph in its own way, it impressed Francis Crick absolutely no end, you see. He seized upon it immediately because he had postulated symmetry and could see that he could generalise the mathematical concept of symmetry. This was a physical principle because various structures aren't built, they don't know about these laws of abstract mathematics and symmetry; they are built to minimise the energy and you can do this provided you can close a structure. And I made all sorts of models and so did Caspar showing how you could build in curvature and there was... this raised quite a lot of attention. And I remember appearing on the Horizon programme, having to jump out of a Buckminster Fuller dome these TV producers' tricks, breaking a plastic cover. And we built some geodesic domes and I also... Buckminster Fuller came to visit us, and as Buckminster Fuller, who, of course, is a... a totally unlettered, he... the... the architects thought him a great mathematician, the mathematicians thought him a crank, you see. He totally, you know... he used... Euler's theorem which relates to the number of vertices... the number of vertices, faces and lines on the polyhedron it's called Euler theorem, it's V plus E minus F equals two, it's known to Euler. And Buckminster Fuller interpreted the two in term of yin and yang a whole lot of balderdash.

But you see these architects; I don't know if you ever read Frank Lloyd Wright, they require all these things to... to stimulate them. So it doesn't matter... how they got there, what they get there is okay. So I was quite impressed by Buckminster Fuller, and I treated him seriously and translated his work, so I... so we made a couple of films together in which he came to Cambridge. And he described it later that he gave Caspar and Klug the mathematics. He didn't understand any mathematics but he... I... these films, I wonder where they are, they're in the archives somewhere because somebody told me they'd seen them at Open University. But the producer of these films died and so I've not been able to trace them, it was quite interesting the time with Buckminster Fuller. He... he was... he lived in a geodesic dome, I was invited, I didn't go to visit his house. I got onto his visiting list and so he would send out, you got a list every month of where he was going to be, which part of the world, including dentist's appointment, you know, anniversaries. But he was a... what he was, was a Yankee inventor in the line of Edison, unlettered but he just, you know, so you have to... I really admire and respect him, but, not as a mathematician or an architect. So that was the beginning, so that was an important paper.