This key-driven, non-printing adding machine is an early example of a Comptometer with a metal case. It has eight columns of plastickeys. The keys in the two rightmost columns, which represent cents, ...

This is the prototype for the Comptometer, a key-driven adding machine invented by Dorr E. Felt of Chicago. It is a scarred wooden box (originally used to transport macaroni) that contains the levers ...

An icon of a desk calendar. An icon of a circle with a diagonal line across. An icon of a block arrow pointing to the right. An icon of a paper envelope. An icon of the Facebook "f" mark. An icon of ...

The centenarian then worked as an accountant at Babysham and was one of the first people to use a Comptometer, the first mechanical calculator, the care home said. Speaking to the BBC, Joyce had a ...

Comptometer from the 1920s, with nines' complements marked on each key The method of complements was used in many mechanical calculators as an alternative to running the gears backwards. For example: ...

She enrolled at Lockyear Business College where she was certified as a comptometer operator. Using this training she worked at Swift & Co. She married Donald R. Gross on December 26, 1948.

Explore items in the Smithsonian's collections related to the year 1908. Held in trust for the American people, the Smithsonian’s collections document our nation’s shared history, art from across the ...

In 1934, Ruth Dorsey founded the Dorsey School to meet the growing demand in business for highly skilled operators of Victor and Burroughs’ comptometer machines. In its day, the comptometer was ...