10/01/1874 Edison, Thomas Alva [supplied or conjectured] -- Articles
(Operator; Gintl, Julius Wilhelm; Stearns, Joseph B) Multiple telegraphy (duplex, quadruplex)
[SM044]  Menlo Park Scrapbook Series: Cat. 1044 (No. 30) -- Telegraph-Duplex, Quadruplex, Multiplex
[SM044045; TAEM 26:126]
Courtesy of Thomas Edison National Historical Park.