Copy letter from John David Griffith Davies, to The Secretary to the Scientific Advisors to the Minister of Production, 2, Central Buildings, Matthew Parker Street, S.W.1 'Dear Sir, Sir Henry Tizard would be grateful if you would forward the attached letter to Dr W B Mann through Dr Alexander King at the British Central Scientific Office in Washington, as the matter is urgent and important. Yours faithfully, [John David Griffith Davies] Assistant Secretary' 13 April 1945