
Telegraph block instrument; Walker's
1865
1865
1934
1872
1839 (original); circa 1988 (replica)
1870
1860
circa 1860
1870
1862-1866
1870-1877
1865-1875
1870
1874
1930 (replica); 1834 (original)
c1860
1864
1888
1860-1866
1865
1873
1866-1870
4000-2001 BCE
1865-1866
1873
1668; 1924
circa 1870
1865-1870
1868
1990-95
1610; 1923
circa 1871
1869
1642-1649 (original); 1883 (model)
1867
1925; 1862
1863
1862-1863
1860-1870
1936
1866
1900-1933 (model); 1869 (original)
1860s
circa 1868
circa 1870
1834-1836
1860
1863
1861-1870
1862
1862