Marine Timekeeper known as 'H5' by John Harrison and Son 1770
1770
1770
1780-1850
1870
1962
1799
1680-1690
1999
1786
1791
1755
1630-85
1700-1815
1700-1725
1830
1625
1823
1640
1790
1680-1685
1700-1725
1708-1710
1928
1801-1819
1675
1814
1690
1700-1725
1650
1680
1800
1702
1680
1660
1640-1660
1622-1628
1630
1660
1680
1790
1755
1690-1695
1700
1660
1730
1807
circa 1801
1630
1853
1924
1650