
Filings coherer, glass tube curved into near U-shape at one end with coil winding at other end, 1894-1904
1894-1904
1894-1904
1894-1904
1900-1910
1894-1904
1894-1904
1894-1904
1894-1904
1898
1894-1904
1900-1910
1894-1904
1899
1900-1910
1894-1904
1894-1904
1894-1904
1894
1894-1904
1895-1900
1894-1904
1900-1910
1894-1904
1894-1904
1898
1894-1904
1894-1904
1899
1900-1910
1898
1894-1904
1894-1904
1894-1904