These documents cover the years 1880-1927. Included is a letter, probably from 1880, to the president of Paraiba do Norte, in which Edison requests permission to send explorer John Branner to search for a vegetable fiber needed to perfect the electric light. Also included is an 1889 letter from Edison to German electrical inventor Werner von Siemens concerning incandescent lamps and dynamos, along with a 1914 letter to Henry Ford, in which Edison describes the deleterious effects of cigarette smoking. A series of letters from the 1920s from Edison to phonograph dealer Mark Silverstone discusses new selling methods, efforts to combine the phonograph and radio, and the sales activities of various phonograph dealers. In addition there is a 1927 letter to Cyril Clemens, president of the Mark Twain Society, in which Edison reminisces about a meeting with Twain at the West Orange laboratory in 1914. Courtesy of the Manuscript Division, Library of Congress.