Addac adding machine
1926
1926
1926
1927
circa 1930
circa 1927
circa 1930
1930
1924
1925
1928
1927
1924
1925
1924-1927
1927
1931
1930
1934
1931
1928
1926
2000-100 BCE
1924
1930-1931
1955; 1830
1925-1928
before 1928
1931
1928
1925-1927
1925
1927-1929
1927
circa 1930
1930
circa 1927
1925
1926-1928
1990-96
1929
circa 1929
1930
1924
1927
1931
1925-1930
1924-1927
1925-1926
1925
1927