
Telephone crossbar switch, Swedish Ericsson, 1921
1921
1921
1871
circa 1900
1910-1912
1772
1866
1930
1955-1970
1998-2004
1987
1991
1900-1980
22 August 1958
1923
1929
1951
1862-1884
1901-1910
1998-2004
1684-1569 BCE; 1998
1905
2001
1766-1769
1789
1926
1951
1937
1911
1739
1965-1975
1800-1818
1965-1975
1900-1980
1800-1818
circa 1900
1935
1945-1955
1965-1975
1912
circa 1953