
Marine Timekeeper known as 'H5' by John Harrison and Son 1770
1770
1770
1762
1755
1762
1762
1762
1761
1762
1762
1762
1760
2000-100 BCE
1755
1770
1755
1769
1757
1762
1762
1762
1767
1755
1761
1761
1761
1762
1761
1761
1766
4000-2001 BCE
1755
1765
1705-1737
1761
1762
1762
1763
1761
1761
1755
1755
1761-1762
1760
1642-1649 (original); 1883 (model)
1936
1990-95
1610; 1923
1766
1960-1979
1668; 1924