
Atomic clock prototype for 'Galileo' satellite, 2002
2002
2002
1960s
1987
1879
1640
1938
1975-1979
1999
Unknown
1800-1825
1800-1825
1839
1893
1973
1965
circa 1990s
1960-1979
1948-02-01
1994
1971-1979
1922-1927
1935-1945
circa 1935
1870-1920
1969
1990-95
1750-1900
1619
1961-1970
1963
1971
1962
1939
1939-1993
1958
1939-1993
1939-1993
1939-1993
1951
1949
1920-1993
1966
1965
1961
1972
1963
1939-1993