
The Ardente Hearing aid, London, England, 1920-1930
1920-1930
1920-1930
1920-1925
1921-1930
1839 (original); circa 1988 (replica)
1926
1920-1929
1930
1920-1925
1925
1928
1921
1934
1931
1927
1924
circa 1930
1928
1922
1928
1926
2000-100 BCE
before 1928
1930-1931
1920
circa 1930
1927
1931
1931
1924
1927
1926
1922-1923
1922-1923
1922-1923
1922-1923
1921-1926
1925
1920-1929
1920-1930
1920-1930
1923
1924-1927
1921
1931
1920
1921-1931
circa 1920
1923
1925
1928