x Note: Photograph 7 of a series of 7. 12 x 16 cm. Seven photographs taken by Albert Bigelow Paine. See Paine, Mark Twain, A Biography, vol. 3, p. 219-20. SLC ordered multiple sets to send to friends. It is accompanied by a sheet of writing paper: "This series of 7 photographs registers with scientific precision, stage by stage, the progress of a moral purpose through the mind of the human race's Oldest Friend. SLC" No. 6 is missing from this set and has been replaced by the printed version cut from a magazine, implying wider publication as well, and the series is accompanied by a (specially?) printed version of the same.