
Marine Timekeeper known as 'H5' by John Harrison and Son 1770
1770
1770
1781-1790
1777-1785
1760-1775
1791
1795
1775
1775
1794
1782-1793
1752
1785-1790
1784
1755
1762
1762
1769
1757
1761
1752
1762
1762
1761
1762
1762
1762
1762
1791
1786
1800
1776
1787
1790
1796
1794
1800
1800
1767
1800
1792
1755
1800
1790
1795
1795
1775-1800
1790
1792
1790
1775-1785