The other important point established by Ponsonby and Thompson, remarkably, was the rotation of Venus. It was in retrograde motion, and that... I... I was very, very sad that that is really the last radar observations which were made at Jodrell bank for two reasons: we were no longer able to compete with the Americans with their possibly building large telescopes like Arecibo and the... the very powerful transmitters, which were necessary to do this work; and secondly, we had the problem of interference with the... with the purely receiving observations at Jodrell. For some time, we had a ring main around the establishment. No doubt it still exists, buried somewhere, in which the... we could protect the... the groups who were using their receivers from whenever we were sending our radar pulses on the telescope.

This became increasingly difficult and for those two reasons, I... with some reluctance, particularly because my original reason for building the telescope was to study the, the cosmic ray air showers by radar, I agreed that we should abandon the radar work with the telescope and this happened in the early 1960s. I think by 1966, we were... we were no longer using the telescope for any radar work. I mean, even... even with a powerful transmitter, which we're using on Venus, we had to be very careful that we never observed below an elevation of about 15 degrees because the radiation would... would have been quite damaging to human beings and we were also extremely careful not to get on the bowl of the telescope at any time when this transmitter might be operating.

Before I end the topic of... of Venus, I, for reasons which I still have to develop, I had very close relations with the Soviet Union and they had... had been... I will mention this separately, but they had constructed a very powerful transmitter at a place called Yevpatoria on the Black Sea coast, and the person in charge of this was Academitian Kotelnikov and I had arranged with him that we would carry out a bistatic observation on the planet Venus, that they would transmit and we would receive and vice versa. My goodness, this collaboration was extraordinarily difficult because either they were using the telescope for some other purpose, or we were using the Jodrell telescope for some other purpose. But in... in effect, we... we did succeed in carrying out these bistatic observations of the planet Venus from this place, Yevpatoria on the Black Sea coast and Jodrell Bank, and there is... there is a short note on that. I do not think it's published in England. I think it was published in one of the Russian Soviet publications.