Marine Timekeeper known as 'H5' by John Harrison and Son 1770
1770
1770
1910
1853-1857
1923
1913
1936
circa 1897
1829-1851
1858
Made late 1700s, modified 1800s
1838
1858
1844
1878
1901-1930
1846
1797-1804
1795
1802
1802
1909
1840-1850
1865-1866
1771
1790-1810
1795-1805
1941
circa 1840
1840
circa 1900
1879
1830
1848-1852
1816
1750
1823
1790
1819-1905
1765
1761
1850
1690-1710
1761
1815
1720-1730
1740
1801-1900
1790-1819
1875