
Marine Timekeeper known as 'H5' by John Harrison and Son 1770
1770
1770
1960
1936
1775-1785
1938
1895
1862
1926
1800
1780
1783-1800
1700-1725
1879
1785-1795
1791
1786
1625
1776
1807
1790
1796
1794
1800
1740-1760
1767
1680
1800
1745
1807
1812
1792
1755
1739
1897
1790
1807
1601-1700
circa 1715
1795
1790
1792
1802
1790
1730
1850-1900
1761-1820
1701-1800
1950-1980