Marine Timekeeper known as 'H5' by John Harrison and Son 1770
1770
1770
1960
1913
1862
1936
1775-1785
1785
1926
1783-1800
1900-1920
1705-1737
1802
1701-1800
1825
1799
1795-1810
1862
1685
1711
1791
1775
1786
1755
1941
1796
1910-1936
circa 1840
1776
1740-1760
1823
1601-1700
1792
1938
1790
1700
1600
1950-1980
1897
1700-1725
1708-1710
1804
1882-1889
1780
1745
1788
1912
1790
1680
1792
1670-1680