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