Addac adding machine
1926
1926
1928
1934
1926
1934
1927
1934
1923
1930
1925
circa 1927
circa 1930
1927
circa 1930
1932
1934
circa 1930
1931
1931
1931
1927
1925
1924-1927
1922-1923
1922-1923
1933
1922-1923
1922-1923
1925
1930
1927
1934
1926
1932
2000-100 BCE
1924
1923
1928
1925-1927
1930-1931
1922
1955; 1830
1932
1933
1925-1928
before 1928
Before 1932
1927-1929
1923
1924