Marine Timekeeper known as 'H5' by John Harrison and Son 1770
1770
1770
1610; 1923
1769
1990-96
1763
1705-1737
1761-1762
2000-100 BCE
4000-2001 BCE
1762
1769
1770
1762
1762
1761
1762
1761
1765
1761
1762
1761
1762
1762
1760
1762
1770
1762
1760
1760-1770
1761
1761
1764
1762
1766
1762
1762
1761
1762
1761
1761
1860-1920
1766
1761
1762
1766
1762
1760-1769
1768-1769
1761
1766