Addac adding machine
1926
1926
1921
1926
1927
circa 1927
1924
1925
1928
1922
1927
1923
1924
1925
1921-1926
1924-1927
1922-1923
1922-1923
1922-1923
1922-1923
1927
1923
1934
1928
1926
2000-100 BCE
1924
1955; 1830
1921
1925-1928
before 1928
1928
1925-1927
1923
1925
1927-1929
1927
circa 1927
1925
1926-1928
1990-96
1922-1925
1929
circa 1929
1924
1927
1922-1924
1923
1922-1923
1922-1923
1922-1923