Copy letter from Herbert Rix, to Henry Clifton Sorby, Fellow of the Royal Society 'Dear Mr Sorby, I will lay your request (with others of a like nature) before the officers when I have the opportunity, I have little doubt that as an exhibitor you will be considered entitled to an extra invitation card. Yours truly, H Rix Asst. Sec. R.S. [Assistant Secretary, Royal Society]'. 2 April 1891