Copy letter from John David Griffith Davies, to Sir Henry Thomas Tizard, Imperial College of Science, S.W.7 Communication, from the Assistant Secretary of the Royal Society, of the decision not to hold an Officers' meeting on 29 May 1941, due to attendance of Tizard and Professor [Archibald Vivian] Hill at a meeting of the Ministry of Supply on the same morning. 22 May 1941