Notched Band Adders

A collection of adders including a Magic-Brain Calculator, an Exactus Mini-Add, a Troncet Arithmographe, and a Locke Adder.

Building on ideas of Perrault and de Caze, in an instrument patented in Russia in 1847 Kummer replaced the wooden rods on an adder with metal bands notched on each side. Kummer’s idea was adopted by the Frenchman Troncet, who published what he called an Arithmographe in the 1890s. Adders with notched bands became the most common form of the instrument sold in the United States in the 20th century.

These stylus-operated instruments generally had a crook at the top of each column, to allow one to move adjacent bands in carrying (or, in some cases, borrowing) a digit. They were manufactured around the world. Occasionally, notched band adders were combined with a slide rule, to ease multiplication and division. A special form of the instrument, designed for computer programmers, aided calculations in base 60 rather than usual decimal arithmetic.

Search term: *:* Date: 1930s Clear All

Ve-Po-Ad Adder

This black and gold notched band adder comes in a maroon cloth-covered cardboard notebook with a rusting stylus. It has eight columns of digits, and nine windows for displaying results. The narrow zeroing rod is at the top.
Description
This black and gold notched band adder comes in a maroon cloth-covered cardboard notebook with a rusting stylus. It has eight columns of digits, and nine windows for displaying results. The narrow zeroing rod is at the top. With the object is a piece of the wrapping in which the adder was sent, showing the postage and date mailed.
With MA.323626, this object is F&T 43 (1&2) from the collection of Felt & Tarrant Manufacturing Company.
The VE-PO-AD (Vest Pocket Adder) was sold by Reliable Typewriter and Adding Machine Corporation of Chicago from at least 1924 through at least 1940.
References: Typewriter Topics, 57 (July 1924) p. 80.
Popular Science Monthly, 126 (January 1933) p. 107.
Popular Mechanics, 73 (January 1940) p. 127A, (February 1940) p. 151A, (March, 1940) p. 123A.
P. Kidwell, "Adders Made and Used in the United States," Rittenhouse, 1994, 8:78-96.
Location
Currently not on view
date made
1937
distributor
Reliable Typewriter & Adding Machine Corporation
maker
Reliable Typewriter & Adding Machine Corporation
ID Number
MA.323627
catalog number
323627
accession number
250163

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