
Marine Timekeeper known as 'H5' by John Harrison and Son 1770
1770
1770
1791
1775
1780
1775
1794
circa 1750
1752
1762
1750-1795
1798
1755
1797
1780
1795
1785-1795
1785
1776-1780
1776-1780
1776-1780
1750
2000-100 BCE
1778
1760-1790
1775-1799
1783
1785
1755
1782-1793
1752
1770
1785-1790
1784
1750-1760
1784
1755
1762
1762
1769
1757
1752
1761
1762
1762
1761
1762
1762
1762
1762
1762