The next critical phase of our work took place at Leeson House. Now, Leeson House was a slight rise above the town of Swanage through which one could look right across over the Bay of Swanage to the Isle of Wight, and I will return to that point in a moment. At that time we were still all concentrating on how to get this elementary air interception system on which we'd seen an echo from an aircraft into... into a Blenheim. Well, I remember one day going to... with Alan Hodgkin, we were being driven to the aerodrome at Christchurch to do something about one of the Blenheims there. And we were talking about how we could possibly scan this narrow beam, which we were now producing from a three-foot paraboloid, because that was about the largest we could get into the nose of the Blenheim, how to scan that to see so that we could get coverage from an appreciable area in front of the fighter. And I remember Alan suddenly saying, 'I know how to do it. We will rotate the scanner in a spiral and because then... and we will rotate using a mag slip the time base of the cathode ray tube in the spiral'. And he said, 'I know how to make the spiral. We will go to an engineering firm and we will have a rotating cylinder, a sliced rotating cylinder and rotating the paraboloid at 1,000 rpm'. What a wonderful device.

We went to Nash and Thompson, and they very quickly made this brilliant engineering device of a spiral scanner, which would rotate at 1,000 rpm, and the sight of that mounted in the nose of a Blenheim was quite fantastic. I mean, one almost felt it was coming towards one of them and it was going to suck one into the aircraft. Other problems that had to be solved was how to use one scanner, one paraboloid for both receiving and transmitting, and you must... it has to be remembered that all of this was on this very high frequency, wavelengths of 10 cm was extremely new. Nothing at all was known about the properties of the radiation. Anyhow, these problems were slowly overcome. I remember Skinner working endlessly on the problems of the crystal mixer and eventually in... with the most amazing speed we had the first flights of this elementary 10 cm air deception equipment in the Blenheim, in March of 1941, and that's amazing. In those few months, the transformation of this ungainly ground equipment into an elegant equipment which would fit into a small night fighter.