Copy letter from Robert William Frederick Harrison, to D Cameron Swan, Swan Electric Engraving Company, Northumbria House, 116 Charing Cross Road, W.C. Referring to his estimate, and in answer to their letter, Harrison regrets to inform Swan that the Royal Society cannot afford the expense of electrogravure work for the portraits of Sir [John Burdon] Sanderson and Professor Williamson, and so are falling back upon collotype. The difference in cost is so great that Harrison does not think swan needs to call again in connection with this particular work. 21 November 1906