Copy letter from Robert William Frederick Harrison, Assistant Secretary of the Royal Society; to Professor [Charles Glover] Barkla, FRS, Physical Laboratory, The University, Edinburgh 'Dear Sir, In reply to your letter of the 1st instant, there is no particular date by which the Bakerian lecture should be in our hands, but we should be glad to receive it as soon as possible in order that there may not be any undue delay in publication.' 05 June 1916