Marine Timekeeper known as 'H5' by John Harrison and Son 1770
1770
1770
1610; 1923
1769
1763
1990-96
1761-1762
1705-1737
c.1750
1752
1755
1750
1755
2000-100 BCE
1762
1750-1770
1755
1771
1769
1750-1766
4000-2001 BCE
1770
1755
1762
1755
1762
1761
1762
1771
1750
1752
1752
1750-1760
1765
1761
1750-1760
before 1753
1762
1761
1762
1761
1752
1755
1762
1750
1750
1770
1752
1760-1770
1761
1762