Copy letter from Herbert Rix, to William Henry Mahoney Christie, Fellow of the Royal Society 'Dear Sir, Will you be good enough to cause us to be furnished with the names of the Second Class Assistants of Six Years' Standing in the Royal Observatory, in order that invitations may be sent to them for the Society's forthcoming Conversazione. Yours truly H Rix Asst. Sec. R.S. [Assistant Secretary, Royal Society]'. 2 April 1894