Marine Timekeeper known as 'H5' by John Harrison and Son 1770
1770
1770
1910
1948-1953
1853-1857
1923
1913
1936
circa 1897
1829-1851
1858
1858
Made late 1700s, modified 1800s
1878
1838
1844
1901-1930
1797-1804
1846
1909
1840-1850
1795
1802
1802
1795-1805
1941
1771
1837
1865-1866
1790-1810
circa 1900
circa 1840
1840
1816
1750
1848-1852
1790
1830
1815
1823
1761
1765
1761
1690-1710
1819-1905
1720-1730
1801-1900
1740
1790-1819
1760-1770