06/09/1885 Edison, Thomas Alva -- Technical Notes and Drawings
Carbon, coal, glass, ceramics; Telephone; Electroplating
[W100DFA]  National Archives, Washington, D.C.: Records of the Patent and Trademark Office (Record Group 241) -- Patent Interference Files -- Weston v. Latimer v. Edison -- Testimony and Exhibits on Behalf of Edison
[W100DFA084B; TAEM 0:0]
Courtesy of the National Archives.