I want to say a few words about the situation in 1943. We had the American objection in the autumn of 1942, when they learned that we were going to... proposing use the cavity magnetron in the H2S System over enemy territory. And, in fact, we were allowed to use it when the soviets defeated von Paulus's Eighth Army in the great battle of Stalingrad at the end of January. Oddly enough, on the very day of that raid, Dee, who was our main supervisor and our Divisional Leader, he received a letter from Robinson, who had been one of the original centimetre development team, and had been sent to America to help the Americans with this new technique. And he wrote a letter to say he completely failed to get the system to work in America, and wasn't it time to do some real scientific investigations?

Well, on that very night, the first raid took place over Hamburg at the end of January 1943. Now, the... in the summer of 1943, the United States Air Force Eighth Army Air Force arrived in England to begin the bombing of Germany. Now, they had been trained in America with the most excellent visual bombsight, and flying at 30,000 feet, under clear skies, they could bomb with great precision. Alas, when they tried this technique, they suffered terrible disasters, and they were given targets such as the ball bearing factory at Schweinfurt, and suffered terrible destruction. And at about that time that this was happening, I was... remember I was at Chippenham, still with the Coastal Command people, working, flying over the Bay of Biscay, and I received an urgent demand to return to Malvern and to Defford, to meet the general who was in command of the Eighth Air Force. And he demanded, with great urgency, that – and this was supported by our own High Command – that we equipped the American Fortresses and Liberators with our H2S equipment, and we did this. We fitted them, in fact, at Defford; my own team did so. And they began operations under cloudy conditions and at night.

Well, before long, the demand by the Americans for the equivalent of our H2S system was so great that the American scientists really got to work on this, and very quickly produced an excellent three centimetre system, which they called H2X, and that was the odd reversal in American policy. Now, after the War, I got to know Rabi quite well, and he had been one of the deputation sent over in 1942, to accuse us of losing the war if we used the cavity magnetron over Germany. And I asked him, and later his biographer, if they had any idea why they could not make the system work in America, when they first tested it in 1942, but I never got a satisfactory answer. And my own opinion is that it was simply the difference between living under the enormous pressure of war in England, and even making a crude system useful, and in America, with... under more peaceful conditions, the drive to make anything work did not exist.