09/23/1875 Edison, Thomas Alva -- Patents -- Caveats
(Serrell, Harold; Walker, George D; Serrell, Lemuel Wright; Smith, Charles H) Electric pen and mimeograph
[W100AAY]  National Archives, Washington, D.C.: Records of the Patent and Trademark Office (Record Group 241) -- Caveats -- Electro Magnetic Paper Perforators for Autographic Writing [case 68]
[W100AAY; TAEM 0:0]
Courtesy of the National Archives.