Marine Timekeeper known as 'H5' by John Harrison and Son 1770
1770
1770
1610; 1923
1712-1713
1769
1701-1752
1728
1735-1745
1717-1725
1720
1763
1990-96
1701-1723
1761-1762
1705-1737
1726-1728
c.1750
1730-1750
1752
1755
1750
1708
1720
1715-1725
1701-1752
1755
2000-100 BCE
1762
1750-1770
1745-1755
1755
1724
1769
1720-1770
1750-1766
1725-1755
4000-2001 BCE
1715-1725
1745
1770
1711
1755
1745-1755
1762
1755
1701-1730
1762
1730-1770
1710
1730
1761