Locke Adder
date: label: date made
content: 1901
name: label: maker
content: C. E. Locke Manufacturing Company
notes: label: Description
content: The first American-made adder to enjoy modest commercial success was developed by Clarence E. Locke (1865-1945). A native of Edgerton, Wisconsin, he graduated from Cornell College in Mt. Vernon, Iowa in 1892. Locke worked for a time as a civil engineer in Minnesota, and then joined his father operating a lumberyard in Kensett, Iowa.
label: Description
content: This version of the device has a metal base with grooves for nine sliding metal rods that move crosswise. Each rod represents a digit of a number being added. Protruding knobs on the rods represent different numerals. The rods are held in place by metal covers, painted black, that extend over the right and left thirds of the instrument. When the device is in zero position, all the rods are in their rightmost position. Numbers are entered by sliding rods to the left, and the result appears in numbers immediately to the left of the cover on the right. The rods are color-coded to distinguish units of money. They lock when depressed, so that they will not slide if the instrument is tilted.
label: Description
content: The locking mechanism, the color-coded rods, and the oval shape of the knobs on the rods are all improvements featured in Locke’s second calculating machine patent, taken out in 1905. This patent is not listed on the instrument. There is no carry mechanism. The instrument sits in a wooden box with no lid. The base of it is covered with red cloth.
label: Description
content: The instrument is marked on the right cover: C.E. LOCKE (/) MFG. Co. It is also marked: KENSETT, IOWA. [/] U.S.A. It is marked on the left cover: THE (/) LOCKE (/) ADDER. It is also marked: PATENTED DEC. 24. 1901. This example came to the Smithsonian from the collection of Felt & Tarrant Manufacturing Company (later Victor Comptometer Corporation).
label: Description
content: References: C. E. Locke, “Calculating Machine,” U.S. Patent 689680, December 24, 1901.
label: Description
content: C. E. Locke, “Calculating Machine,” U.S. Patent 779088, January 3, 1905.
label: Description
content: Robert Otnes, “Sliding Bar Calculators,” <I>ETCetera</I> #11 (June 1990): pp. 6-8.
label: Description
content: P. Kidwell, “Adders Made and Used in the United States,” <I>Rittenhouse</I>, 8, (1994): pp. 78-96.
label: Location
content: Currently not on view
place: label: place made
content: United States: Iowa, Kensett
topic: label: Subject
content: Mathematics
setName: label: See more items in
content: Medicine and Science: Mathematics
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content: Adder
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content: Science & Mathematics
creditLine: label: Credit Line
content: Gift of Victor Comptometer Corporation
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: MA.323619
label: catalog number
content: 323619
label: accession number
content: 250163
objectType: label: Object Name
content: adder
physicalDescription: label: Physical Description
content: wood (overall material)
label: Physical Description
content: metal (overall material)
label: Physical Description
content: cloth (overall material)
label: Measurements
content: overall: 2.5 cm x 29 cm x 11.3 cm; 31/32 in x 11 13/32 in x 4 7/16 in