
Marine Timekeeper known as 'H5' by John Harrison and Son 1770
1770
1770
1781-1790
1777-1785
1760-1775
1791
1795
1775
1775
1794
1755
1782-1793
1752
1770
1785-1790
1784
1750-1760
1784
1755
1762
1762
1769
1757
1761
1752
1762
1762
1761
1762
1762
1762
1762
1762
1791
1786
1800
1776
1787
1770-1780
1790
1796
1794
1800
1800
1767
1800
1760
1792
1795
1755
1800