Marine Timekeeper known as 'H5' by John Harrison and Son 1770
1770
1770
1960
1862
1913
1936
1775-1785
1785
1926
1783-1800
1705-1737
1900-1920
1802
1701-1800
1825
1862
1685
1799
1795-1810
1711
1941
circa 1840
1786
1755
1791
1775
1910-1936
1776
1796
1740-1760
1792
1601-1700
1823
1700
1938
1790
1897
1788
1700-1725
1784
1882-1889
1950-1980
1745
1600
1708-1710
1780
1804
1785-1795
1912
1800
1790