George III's pendulum
1762
1762
1762
1944-1947
1776
1640-1662
1844-1929
1923-1925
1930-1940
1940
1825
1927-1930
1840-1878
patented 1947
1956
1932
1671-1730
1962
1924
c.1890
1881
patented 1947
patented 1947
1973
1912-1922
patented 1947
1800-1900
1701-1800
1927
1834
1827
1825
1818
1915-1984