This machine performed essential the cranking operation of earlier calculators, such as the Monroe machine, with single button pushes. Frank Stephen Baldwin 1839-1925. This 10-key calculator provides accurate manual computation. Each complete forward turn of the large crank on the right will add the value set into the 8 x 10 keys into the bottom register of the carriage. The top register counts the turns.
Subtraction is achieved by turning the crank in reverse.
To multiply the Repeat button is pressed and the crank turned as often as needed for the low-order digit. The crank on the carriage is for resetting result and counter registers. Division is performed by subtracting the divisor left to right. G3.3, F2.5 Table of Integrals and functions. Side panels removed.