Marine Timekeeper known as 'H5' by John Harrison and Son 1770
1770
1770
1610; 1923
1712-1713
1769
1728
1717-1725
1735-1745
1730-1750
1720
1990-96
1763
1726-1728
1705-1737
c.1750
1761-1762
1750
1752
4000-2001 BCE
1745-1755
2000-100 BCE
1715-1725
1769
1720-1770
1715-1725
1755-1765
1724
1750-1766
1750-1770
1762
1711
1745
1745-1755
1725-1755
1770
1745-1770
1745-1755
1755
1762
1730-1770
1761
1762
1710
1759
1750
1740-1760
1752
1761
1752
before 1753
1765