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Mechanical Calculator

L.E. Jones

This object is a dark green mechanical calculator in a wooden box. The calculator consists of a bank of slots with sliding mechanisms that allow adjustment of a row of rotating number wheels at the top, with two sliding markers above. A swinging bar can be raised to return all these adjusters to zero. Beneath this is a second row of rotating number wheels located on a carriage, with sliding markers above. Various handles and levers on the side of the machine allow returns to zero, adjustment, and calculation. At the top left, there is a lever that allows the user to switch between “+” and “-“. To the right of the carriage there is a small metal dome-shaped bell.

The calculator can be removed from the box. It has four round feet that fit in purpose-cut. felt-lined holes in the base of the box. At the roof of the box, a thick piece of felt serves to cushion to the top of the calculator and hold it in place. The box has a metal key to lock it and a molded plastic handle on the lid. A piece of cotton string ties the key to the handle.

Accession Number: 2017.lej.55

Alternative Name: Arithmometer

Primary Materials: Wood, Metal, Plastic


On the body of the calculator: “WALTHER”

At the back of the calculator on two small metal labels: “Modell WR16 WALTHER No 62933”
“WALTHER B├╝romaschinenges. KG. Niederstotzingen/ Wttbg.”

Dimensions (cm):

Box: 32cm x 19cm x 17.5cm Calculator: 30.8 cm x 14cm x 13.5cm


To facilitate the addition, subtraction, multiplication and division of numbers.


Good. The exterior of the calculator has some minor scratches and smudges, indicating some use. The metal pieces of the mechanism are dulled but only slightly corroded. It is likely that the interior of the mechanism has seized up.

Associated Instruments:

Manufacturer: Walther

Date of Manufacture: c. 1930s


This object was donated by the University of Toronto Archives, where it had been stored for some years.

Additional Information and References:

Historical Notes: