The Making of Modern Britain
An example was brought to Washington, luckily being recovered after it was nearly lost at Euston station. The cavity magnetron, even apart from the other secrets, was a war-changing device, described by one US historian as "the most valuable cargo ever brought to our shores".
When Tizard finally arrived in the US after a stopover in Canada he was brought to see President Roosevelt, smuggled into the White House by a back door to avoid photographers in what was still a pro-neutrality Washington atmosphere. There followed, between the British mission and US military chiefs and scientists a kind of intellectual strip-poker, with both sides playing "I'll show you mine, if you show me yours" until the British secrets had been handed over. Not all of them this time, however: the process of passing over the full breakthroughs by two exiled German scientists on the nuclear bomb, and then teams of British nuclear scientists, would come later. Tizard had been an early convert to the possibilities of nuclear power. His pre-war warnings to the Belgian owners of the world's only uranium mine, in the Congo, resulted in shipments going to America which would end up in the world's first atomic bomb. For now, he only passed on general details to scientists in the US, who were skeptical about the British approach. It was the same story with Frank Whittle's jet engine. This humbly born, risk-taking and anti-
Establishment RAF officer turned scientist had been working for years on jet propulsion. In the late 1930s he nearly lost everything thanks to official lack of interest: the delay would be part of the reason that the Germans were flying jets nine months ahead of the RAF. But in 1940-41 Whittle was far ahead of the Americans. Again, Tizard dropped hints.
The British got little useful information in return. Details of the latest US bomb-sight were withheld even after Pearl Harbor. But a full exchange of facts was not really Tizard's aim. He thought British industry, much of it outdated before the war and much of it being heavily bombed now, could not hope to produce the radar gear, never mind atomic bombs, that the larger and protected American industrial base could. Not, at least, if she was building tens of thousands oa warplanes, tanks and guns at the same time. Like Churchill, he was sure that The US would be drawn into the war whether Britain was beaten or not: if so, they needed to be as strong