Copy letter from Herbert Rix, to Arthur Keen, 4 Raymond Buildings, Gray's Inn, W.C. 'Dear Mr Keen, For a job likely to run beyond £10 we get an estimate, otherwise Drake & Gorham work without. Dr. Foster will write to you and make an appointment to see about the diagrams. Yours truly, H Rix Asst. Sec. R.S. [Assistant Secretary, Royal Society]'. 28 July 1893