Addac adding machine
1926
1926
1920-1925
circa 1927
circa 1930
1922-1923
1922-1923
1922-1923
1922-1923
1921
1926
1924
1927
1934
1923
1920-1929
circa 1920
1955; 1830
1924-1927
1928
1927
circa 1930
1920-1929
1920
1930
1924
1925
1928
1927
1925
1927
circa 1920
1926
2000-100 BCE
1920-1928
1925
1921-1926
1930
1923
1920-1930
1928
1920
1922
1921-1930
1920-1930
1921
1925-1928
before 1928
1927-1929
1925-1927
1923