Url https://edisondigital.rutgers.edu/document/PT005A1 Resource class dctype:Text Title [PT005A1], Patent Specification, Thomas Alva Edison, April 9th, 1873 Creator Edison, Thomas Alva Subject Multiple telegraphy (duplex, quadruplex) Publisher Thomas A. Edison Papers, School of Arts and Sciences, Rutgers University Date 1873-04-09 Type Patent Specification Identifier PT005A1 Source 8:552 Relation Munn & Co Goepel, Paul Rights Thomas Edison National Historical Park Date Created 1873-04-09 Has Version https://archive.org/details/edisonmicrofilm8/page/n560/mode/1up Archive.org Viewer, Microfilm Series Reel 8 Is Part Of PT005A-F Uri https://edisondigital.rutgers.edu/document/PT005A1 https://edisondigital.rutgers.edu/document/PT005A1 --