Singer came more or less on his own bat. He had a sabbatical and he just wrote to me saying he was coming. At that stage I didn't know Singer as well as I did some of the other people, like Bott, and nor did I have the kind of resources to invite people anyway, you know. I remember when I went to Oxford the resources to invite people were extremely limited. I remember I got Serre to come over and give a seminar and I think I... I had great difficulty in extracting £5 out of the university or something, you know. It was extremely difficult. So there was no way I would have had money to invite Singer from America, but he came... he came on his own here, he had a sabbatical and he liked to come and stay in Oxford, and so, I got to know him really after… well after he came, but that was the contact.

Subsequently things improved and eventually I got Bott to come, as a Visiting Fellow to St Catherine's, and that was a great success. But in the early days it wasn't easy to invite visitors, but Americans frequently came on their own, had their resources and moved around. And that's why I spent time going elsewhere, and by going to sabbaticals elsewhere, to America every couple of years, going to conferences, going to Bonn.  That's where I made my contacts. The number who came to Oxford would have been in those days… early days, much more limited, yes.