Copy letter from Herbert Rix, to Sir George Gabriel Stokes, President of the Royal Society 'Dear Sir, The letter referred to in the enclosed appears to have been sent to you during my vacation. Possibly it did not reach you. At any rate, the present communication seems to contain all necessary data for a judgement. I suppose if the author desires the translation of his paper it is very much a matter of form to grant permission? Yours obediently Herbert Rix'. 5 October 1889