Copy letter from Herbert Rix, to Professor Benjamin Williamson, Fellow of the Royal Society 'Dear Sir, The volume for which you ask is a rare one. We cannot let it travel by book-post, but one sending it by parcel-post with plenty of packing. Please, when you return it to us, return it in the same way. It must be sent back strictly within the month. I am, faithfully yours, Herbert Rix Asst Sec RS [Assistant Secretary, Royal Society]'. 24 January 1889