Papers on "The Just-Perceptible Difference" Contains: First proof and MS draft of Francis Galton's "The Just-Perceptible Difference"; MSS of "Measure of the Imagination" and "Optical Continuity", being the second and third parts of the lecture on "The Just-Perceptible Difference", but also published as independent papers in Nature; MSS of "Signals", "Likenesses" and partial draft of "Story of the Teeth"; Diagrams, photographs and models of figures used to illustrate Galton's lecture; References from books on the senses, and copy of Photographic Work; Letter from Galton on erroneous figures in telegrams. 1893