Mechanical Accountant Simplex

Key driven adding machine

1902

This American adding machine of the Mechanical Accountant Company, Providence, Rhode Island, with the low machine no. 1049, is an early model of the Simplex series, which not only has a rotary wheel for clearing both counters (setting control and result movement), but also a long key below the keypad for clearing the setting control (important for checking the entered values). The early simplex models are only set up for working in columns; several keys can only be pressed at the same time if none of the keystrokes has to handle a tens transfer, otherwise the tens transfer will be lost. This deficiency is fixed in the later duplex models. The designer of this key-driven two-species machine is J.A.V. Turck, who was later (from about 1910) employed as a designer at the company Felt and Tarrant (see Comptometer) and wrote one of the most important standard works (Turck [1921]) on the history of calculating machines. The duplex version was built until 1920. The machines were distributed directly to the consumer by mail. This early model Simplex was offered with half and - like this one - with a full keyboard. A Simplex model with machine no. 1372 is in the former Brunsviga collection (today Braunschweigisches Landesmuseum) and is dated 1903.