Copy letter from Robert William Frederick Harrison, Assistant Secretary of the Royal Society; to F. G. Selby Esquire; Secretary of the Advisory Committee for Aeronautics 'Replying to your letter of March 12th, it will be quite convenient for you to have the use of a room at the Royal Society for the meetings of the Advisory Committee for Aeronautics on the following dates, and I have made a note of them: Aerodynamics Sub-Committee, April 1st, 2.30pm Engine Sub-Committee, April 8th, 11am Advisory Committee, April 8th, 3pm.' 14 March 1919