Amplion loud speaker with wooden horn, 1925
1925
1925
1921-1926
1924-1927
1922-1923
1922-1923
1922-1923
1922-1923
1920-1929
1914-1918
1920-1935
1920-1930
1934
1927
1936
1923
1931
circa 1920
1930
1934
1910
1913
1936
1931
1918
1934
1928
1935
1926
2000-100 BCE
1920-1928
1910-1936
1936
1920-1936
1917-1918
1910-1930
1924
1925-1935
1914-1918
1929-1935
1915
1914-1918
1921-1931
circa 1920
1910-1933
1930-1931
1935
1914
1914
1935
1955; 1830