Copy letter from Herbert Rix, to J E Watkins, Curator, Technological Collections, United States National Museum, Smithsonian Institution, Washington In answer to Watkins' of the 1 [July], Rix wrote to Watkins at the Field Columbian Museum on 13 November 1894 concerning the cost of a photograph of the Survey Engine. He is afraid the letter never reached Watkins and quotes what he wrote, noting the price of the negative and two silver prints would be 27 shillings and six pence. 11 July 1895