Copy letter from Robert William Frederick Harrison, to Dr Henry Edward Armstrong, Fellow of the Royal Society 'Dear Dr Armstrong, I enclose herewith receipt for your annual contribution. Referring to your note ^addressed^ to Mr White, of yesterday's date, I have sent a set of the Index Schemes to Prof. [Professor Christian Felix] Klein as requested therein. I am, faithfully yours, Rt Harrison Asst. Sec. RS. [Assistant Secretary, Royal Society]'. 16 May 1896