Moving magnet galvanometer with dial inscribed "Greenwich Mean Time", 1843-1897
1843-1897
1843-1897
1831
1900-1950
1857
1966-1970
1900-1920
1900-1920
1900-1920
1900-1920
1900-1920
1900-1920
1900-1920
1900-1920
1900-1920
1900-1920
1900-1920
1940-06-15
1870-1900
1868
1857
1900-1920
1900-1920
1900-1920
1900-1920
1900-1920
1900-1920
1900-1920
1900-1920
1900-1920
1900-1920
1900-1920
1900-1920
1939
1939
1937-02
1938-11
1906-1907
1925-1935
1930