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