Copy letter from Herbert Rix, to Hugh Longbourne Callendar, 2 Princes Mansions, Victoria Street 'Dear Sir, The Secretaries are of the opinion that your plates will be improved in appearance as well as costing less if we can make two instead of 3 quarto plates, as in the accompanying sketch plan. But before putting them in hand I am to inquire whether the arrangement meets your approval. Yours truly Herbert Rix Asst. Sec. RS [Assistant Secretary, Royal Society] P.S. I must explain that the paper is not yet voted for publication, but that I am taking all preliminary steps so that it may be put in hand at once if the verdict is favourable'. 13 February 1891