Blondel triple bifilar oscillograph, 1900
1900
1900
1930
1950-1970
1931
circa 1970
circa 2002
1761
1946-1960
1997
1960-1964
1871-1890
1942-1945
1886-1930
1960-1964
1886-1930
1871-1890
1972
1830-1840
1871-1890
1950-1951
1890
1887
1871-1890
1986
1970-1977