Locke Adder
date: label: date made
content: 1905
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 bronze-colored metal covers 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.
label: Description
content: 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. 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. There is no carry mechanism. The base of it is covered with green 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 (/) JAN. 3 1905. The instrument fits in a cardboard case covered with black cloth.
label: Description
content: According to the donor, the example of the Locke adder was given to him by the retiring operator of a country milk receiving station for a dairy. The operator used it to determine the total number of pounds of milk received each day at the station.
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: Description
content: Accession file, for advertising brochure and history of the instrument.
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 Earl L. Hemenway
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: MA.321327
label: catalog number
content: 321327
label: accession number
content: 243137
objectType: label: Object Name
content: adder
physicalDescription: label: Physical Description
content: paper (overall material)
label: Physical Description
content: metal (overall material)
label: Physical Description
content: cloth (overall material)
label: Measurements
content: overall: 2 cm x 29.5 cm x 12.3 cm; 25/32 in x 11 5/8 in x 4 27/32 in