
Strowger step-by-step automatic telephone exchange switch, 1897-1898
1897-1898
1897-1898
1898
1801-1840 (original); 1901 (model)
circa 1900
1898
1899
1901
2000-100 BCE
1895
1901
circa 1900
1899
1897
circa 1900
1898-1900
1901
1900
1895
1896
circa 1897
1896
1895-1899
1896
1898-1899
1894
1901
1892
1899
1895-1900
1900
1899
1899
1899-1901
1934
1901
1898
1891-1900
1900
1872 (original); 1909 (model)
1955; 1830
1892
1892
1898
1901
1901
1898
1896
1893-4
1896
1901