Copy letter from Herbert Rix, to Professor Stewart 'Dear Sir, We are sending you today your proof for further corrections & notes as per your letter to Lord Rayleigh. The expense of these particular corrections will be debited to you. If you will return the proof to us with the corrections made, we will put in the cut & let you have a complete revise of the whole. Yours truly H Rix Asst Sec [Assistant Secretary]'. 7 July 1893