
Marine Timekeeper known as 'H5' by John Harrison and Son 1770
1770
1770
1775
1744-1774
1775
circa 1750
1745-1755
1752
1762
1755
1735-1752
1762
1762
1745-1755
1745-1755
1735-1754.
1752
1762
1761
1762
1762
1762
1760
1740-1749
2000-100 BCE
1778
c.1750
1750
1755
1750
1752
1770
1738-1777
1750-1760
1755
1735-1753
1769
1757
1762
1762
1762
1776
1767
1740-1760
1745
1755
1739
1750-1760
1765-1775
1745-1755
1761