George III's pendulum
1762
1762
1751-1800
1783
1785
1785
1778
1762
1769
1755
1761
1750-1795
1761
1782-1793
1776
1757
1784
1762
1784
1785-1790
1762
1798
1762
1762
1752
1752
1762
1752
1762
1755
1750
1794
1750-1800
1782
1787
1764
hallmarked 1788
1762
1762
1756-1800
1770
1755
circa 1750
1780-1800
1750-1766
1796-1797
1796-1798
1771-1800
1785-1789
1771-1800
1750-1800