Addac adding machine
1926
1926
1928
1935
1936
1934
1926
1934
1927
1936
1930
circa 1927
circa 1930
1927
circa 1930
1935
1935
1932
1931
1931
1927
1927
1934
1926
2000-100 BCE
1936
1929-1935
1928
1935
1935
1930-1931
1936
1935
1955; 1830
1932
1933
Before 1932
1932
1933
1934
1930
1929-1935
1934
1935
before 1928
1927-1929
circa 1930
1928
1931
1935
1930-1935