Addac adding machine
1926
1926
circa 1927
1924
1926
1927
1934
1927
1926
2000-100 BCE
1927
1955; 1830
1927
circa 1927
1990-96
1930 (replica); 1834 (original)
1926
1927
1934
1839 (original); circa 1988 (replica)
1801-1892 (prepared); 1946 (element replaced)
1926
1926
1903 (original); 1982 (model)
4000-2001 BCE
1830 (original); 1967 (model)
1927
circa 1926
circa 1926
1953-4
1926
1926
1926
1927
1927
1927
1927
1970-1900
1927
1927
1927
1970-1875
30 CE
30 CE
1927
2686-2613 BCE
1926
circa 1927
1926
1859; 1986
1945-50