So Mössbauer spectroscopy was well established, and Terry and I had written a book on it, we’d become well known throughout the world, and that had two effects: the first was in coming down to Leeds I was able to build up a dedicated large laboratory space with many Mössbauer spectrometers and good access to liquid helium. On the other hand, it meant that, because of our growing reputation, people were coming from all over the world, with their own money, to work in the group both as post-doctoral fellows, if they’d won a scholarship from their own country, or from visiting members of staff, people came on sabbatical leave, and so forth.

So that work went very well, and I suppose the main thing from the point of view of our discussion now is that we picked compounds clearly that could be solved in iron chemistry and tin – tin 119 was a moderately easy isotope – but I thought we should also try some of the more difficult ones, that is to say, more difficult technically from the Mössbauer effect.