Addac adding machine
1926
1926
1930-1940
1926
1927
1938
1938
1938
1935
1938
circa 1930
1940
1940
1936
1934
1929-1935
1937
1937
1938
1938
1932
1930-1940
circa 1938
1935
circa 1927
circa 1930
1930
1935
1928
1927
1924
1934
1927
1936
1931
1930
1934
1938
1936
1931
1934
1928
1935
1926
2000-100 BCE
1936
1938 and 1951
1929-1935
1940
1938-1940
1937-1938