Copy letter from Robert William Frederick Harrison, Assistant Secretary of the Royal Society; to Messrs. B. F. Stevens & Brown, 4 Trafalgar Square, W.C. 'Dear Sirs, With further reference to your photgraphing a document from our Archives, I think we can furnish you with the facilities you require, if you would be good enough to give us twenty-four hoursnotice that your photographer will call. I suggest that he should come in the forenoon at 10 or 11 o'clock.' 5 May 1916