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