
Henley needle galvanometer, 1855-1860
1855-1860
1855-1860
1865
1857-1858
1857-1858
1858-03-02
1866
1857-1858
1867
1866
1862
1857
1865
1860
1868
1772 (original); 1919 (model)
1853-1857
1858
1801-1840 (original); 1901 (model)
1775-1799 (original); 1900-1907 (model)
c1860
1869
1864
1925; 1862
1888
1858
1858
1856
1859
1854
1858
1860-1866
1856-1857
1865
4000-2001 BCE
1855-1865
1855
1856
1856
1860
1855
1865
1855
circa 1860
1930 (replica); 1834 (original)
circa 1860
1857
1862
after 1859
1858-1866
before 1857