
Filings coherer, glass tube formed into T-shape at one end and bent round into U-shape at other end with bulb, 1899
1899
1899
1890-1896
1894-1904
1894-1904
1890-1894
1899-1901
1894-1904
1934
1894-1904
1894-1904
1894-1904
1898
1894-1904
1900
1896
1892
1897
2000-100 BCE
1890-1900
1891-1900
1902
1890-1899
1872 (original); 1909 (model)
1898
after 1903
1892
1904
1888
circa 1905
1890
1898
1899
1890
1899
1905
1896
1895-1899
1898-1900
1900
circa 1900
circa 1900
1889
circa 1890
circa 1890
circa 1890
circa 1890
1897
1901
1889
circa 1900