Section of model "F" controlled-key Comptometer by Felt and Tarrant Manufacturing Co.
1921
Section showing construction of Burroughs hand operated adding and calculating machine (non-listing) class 5
1929
Cut-away demonstration model of Walther WSR 160 calculating machine
Section showing construction of the earlier hand operated model of Burroughs adding and calculating machines
1929
Section of a Comptometer by Felt & Tarrant showing mechanism
1908-1909
Glass encased sectional model of Comptometer by Felt & Tarrant
1927-1928
Working model of a Leibniz stepped reckoner
1937
Small trial piece for calculating machine invented by Charles Stanhope in 1777 with case
1777
Stripped model of a "Curta" pocket calculating machine with cylindrical metal case
1950-1951
Stripped down model of a "Curta" pocket calculating machine
1950-1951
Small trial piece for calculating machine invented by Charles Stanhope in 1777
1777
Spare parts for working model of a Leibniz stepped reckoner. Consisting of coiled steel spring
1937
Working model of a Leibniz stepped reckoner
1937
Working demonstration of barrel calculating machine mechanism
1978-1980