Book, Applied Mechanical Arithmetic As Practiced on the Controlled Key Comptometer

Book, Applied Mechanical Arithmetic As Practiced on the Controlled Key Comptometer

Usage conditions apply
This book was prepared by the Felt & Tarrant Manufacturing Company in 1914 (this copy is a 1920 revision) to publicize its Comptometers and to train prospective buyers in the use of these devices. In the late nineteenth century, Dorr E. Felt (1862-1930), one of the partners, invented an adding machine which did not allow imperfect key strokes and which sounded a bell to remind the operator to clear out an old problem before beginning to input new data. This manual for the Comptometer contains a slightly-rewritten version of the machine's history, instructions for use, a very typical early-twentieth-century efficiency study of the time and money saved by the Comptometer (pages 12-13, 18), and hundreds of pages explaining how to employ the Comptometer in every bookkeeping and calculating task imaginable. There were applications for industries from bakeries, creameries, and dairies to pumping stations and railroads. There are numerous photographs and illustrations in this book, including advertisements, depictions of male and female clerks at work, and sample documents demonstrating the machine's applications. At some point in its history, this book sold for $1.50. NMAH received this book along with accession 1989.0325, several Comptometers and slide rules donated by Myron R. Smith, a collector from Kirkland, Washington.This copy is almost entirely clean.
Peggy Aldrich Kidwell, "‘Yours for Improvement'–The Adding Machines of Chicago, 1884-1930," IEEE Annals of the History of Computing 23, no. 3 (2001): 3-21.
Currently not on view
Object Name
date made
From 1920
Felt & Tarrant Mfg. Co.
place made
United States: Illinois, Chicago
Physical Description
paper (overall material)
overall: 3.4 cm x 17 cm x 14.8 cm; 1 11/32 in x 6 11/16 in x 5 13/16 in
ID Number
nonaccession number
catalog number
Credit Line
Gift of Myron R. Smith
See more items in
Medicine and Science: Mathematics
Adding Machines
Data Source
National Museum of American History
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