Burroughs Class 5 hand operated mechanical adding machine with ten registers
1920-1925
1920-1925
1921
1923
1925
1925
circa 1920
2000-100 BCE
1924
circa 1920
1922
1955; 1830
1925
1922-1923
1922-1923
1923
1934
1922-1923
1922-1923
1920
1920
1921
1920-1925
1924
1923
circa 1920
1920
1990-96
1920
1925
circa 1920
1922-1925
1922-1925
1922-1924
1925
1921
1924
1930 (replica); 1834 (original)
1801-1892 (prepared); 1946 (element replaced)
1922
1924
1923
1924
1922
1920
1903 (original); 1982 (model)
1925
1922-1923
1934
1922-1923
1920-1922