
Bain's chemical telegraph, 1850.
1850
1850
1858
1853-1857
1853-1857
before 1857
1839 (original); circa 1988 (replica)
1775-1799 (original); 1900-1907 (model)
1850
1851
1850-1859
1851
1850-1859
circa 1854
1850
circa 1854
1856
1893-4
1934
1850
1853
1854
1853
1852
1955; 1830
1850
1858
1859
1858
1858
1855
1856
1851
1857-1858
1857-1858
1857-1858
1863-7
1858-03-02
1851
1852
2000-100 BCE
1850-1857
1855
1857
1851
1854
1855
1858
1850-1856
1852
circa 1854