
One of Fleming's first thermionic diode valves, 1889
1889
1889
1839 (original); circa 1988 (replica)
1801-1840 (original); 1901 (model)
1888
1889
1888
1889
1872 (original); 1909 (model)
1889
1934
before 1889
before 1889
1893-4
2000-100 BCE
1955; 1830
1889
1990-96
1830 (original); 1967 (model)
1775-1799 (original); 1900-1907 (model)
1889
1930 (replica); 1834 (original)
1889
1925; 1862
1705-1737
1888
1934
1772 (original); 1919 (model)
before 1889
1889
4000-2001 BCE
1990-95
1668; 1924
1976; 1776
1610; 1923
1834-1836
300 BCE; 1905-1915
1929 (copy); 1702-1714 (original)
1889-02
circa 1888
1888
1889
1889
1889
1889
1889
1889
1888-1889
1888
1936
1888