Copy letter from Herbert Rix, to Edwin Tulley Newton, Fellow of the Royal Society 'Herewith new proof of plate 6 and the same old proofs of plates 1 and 9. Plate 6 has been treated as you surmised, and requires no new negative, but the other two would have to be completely remade if they are to be altered. I daresay the Cambridge Co. could be induced to bear the expense of this, but in any case the delay would be very considerable, as they assure me. I hope, therefore, you will pass these, as the plates are, on the whole, I think, fairly satisfactory'. 4 October 1893