
Marine Timekeeper known as 'H5' by John Harrison and Son 1770
1770
1770
1775
1744-1774
1780
1775
circa 1750
1745-1755
1752
1762
1755
1735-1752
1729-1753
1762
1762
1745-1755
1745-1755
1735-1754.
1752
1762
1761
1762
1762
1762
1770-1780
1780
1760
1740-1749
2000-100 BCE
1725-1755
1778
1776-1780
1776-1780
1776-1780
1725-1775
c.1750
1750
1755
1750
1752
1770
1738-1777
1750-1760
1755
1735-1753
1769
1757
1762
1762
1762
1776