
Marine Timekeeper known as 'H5' by John Harrison and Son 1770
1770
1770
1960
1936
1938
1625
1795-1810
1926
1791
1786
1776
1807
1650
1790
1796
1800
1800
1794
1780
1783-1800
1767
1740-1760
1680
1800
1745
1601-1700
1700-1725
1807
1812
1879
1792
1755
1739
1897
1790
1807
1601-1700
circa 1715
1795
1790
1785-1795
1792
1802
1790
1730
1895
1761-1820
1701-1800
1862