Marine Timekeeper known as 'H5' by John Harrison and Son 1770
1770
1770
1610; 1923
1769
1763
1990-96
1772 (original); 1919 (model)
1705-1737
1761-1762
1755
2000-100 BCE
4000-2001 BCE
1762
1771
1769
1770
1755
1755
1762
1762
1761
1771
before 1753
1761
1765
1761
1762
1761
1762
1755
1762
1760
1770
1762
1762
1755
1761
1772-1773
1761
1760
1762
1764
1760-1772
1766
1762
1762
1761
1762
1772
1761
1758-1773