![](https://coimages.sciencemuseumgroup.org.uk/37/620/large_thumbnail_1961_0057__0002_.jpg)
Amplion loud speaker with wooden horn, 1925
1925
1925
1921-1926
1933
1922-1923
1922-1923
1922-1923
1922-1923
1920-1930
1998-2002
1934
1936-1955
1884-1936
1927
2000-2006
1955-1960
1955-1985
1883-1930
1923
1936
1946
1920-1929
2001
1977
1924-1927
1936-1955
1935
1920-1930
1946-1948
1925-1946
1939
1910-1960
1916-1972
1937-1960
1926
1906-1965
1906-1915
1953
May 1953
2008
1936
1951-1953
1920-1936
1944-1945
1924
1925-1935
1935-1965
1906-1916
1938 and 1951
1929-1935
1928