Copy letter from Sir Henry Thomas Tizard, to Professor J Proudman, The University, Liverpool 3. 'Dear Proudman, I have written as you suggest to the Secretary of Admiralty and sent a copy of the letter to Sir John Edgell, I have also written to Professor Pettersson to tell him that we should be glad to welcome him here if he can pay a visit to England in the near future. Yours sincerely, [Sir Henry Thomas Tizard] Foreign Secretary R.S. [Royal Society]' 12 September 1945