Photogaphic print and diagram, showing showing secondary beta-rays ejected from air and from a copper screen by X-rays
1920-1930
1920-1930
1947
1937
1947
1937
1920-1926
1920-1926
1937
1933-1937
1950
1920-1926
1945-1948
1961
1920-1930
1947
1947
1920-1930
1936-1937
1945-1948
1920-1930
1956
1843
1969
circa 1851
1851
circa 1851
1846
circa 1851
1849
circa 1851
circa 1870
circa 1870
circa 1870
circa 1870
circa 1870
circa 1870
circa 1850
circa 1850
circa 1850
circa 1850
circa 1850
1849
circa 1850
circa 1850
circa 1850
circa 1850
circa 1850