Copy letter from Herbert Rix, to Professor Michael Foster, [Royal Society] 'Herewith enclosed, estimate for [Henry Enfield] Roscoe & [Joseph] Lunt's plates. The authors got proofs executed before they sent the paper in, but of course we are not bound by that. This, however, is the estimate for plates from these proofs. If you can accept it, please return it to me. If not without Treasurer's sanction please send it to him to send to me. He is at home now. Yours truly Herbert Rix'. 20 July 1891