1870s 1880s 1890s 1900s 1910s 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s
1872
1874
◀

1873

▶
Western Union contracts with Thomas Edison and Elisha Gray to solve telegraph multiplexing
Thomas Edison Elisha Gray
PDF: Western Union Annual Report 1873
Western Union Annual Report 1873
Photo: Western Union contracts with Thomas Edison and Elisha Gray to solve telegraph multiplexing
Western Union contracts with Thomas Edison and Elisha Gray to solve telegraph multiplexing
Elisha Gray demonstrates his 'harmonic telegraph' to Western Union
Elisha Gray demonstrates his 'harmonic telegraph' to Western Union