Comptometer Model A
date: label: date made
content: 1904
name: label: maker
content: Felt & Tarrant Manufacturing Company
notes: label: Description
content: This key-driven, non-printing adding machine is an early example of a Comptometer with a metal case.
label: Description
content: It has eight columns of plastickeys. The keys in the two rightmost columns, which represent cents, are white, the three middle columns are black, and the three lftmost columns are white. Such color coding was common in machines designed for financial calculations. Complementary numbers are indicated. The keys are alternately concave (for odd digits) and flat (for even digits). The keys are worn, and one is missing. The key stems are flat, and become progressively longer as the digits become larger. The subtraction levers are at the same level as the decimal markers.
label: Description
content: The nine numeral wheels are white or turquoise around the rim, depending on the decimal place of the digit indicated. They are visible through windows in the glass. The zeroing handle is on the left. The Model A Comptometer was Felt & Tarrant’s first “duplex” machine, in that it would add in more than one column at a time, each column having the capacity to add, receive, and carry simultaneously. This was not true of the earlier wooden box models.
label: Description
content: The first Model A Comptometer was produced in January 1904 and had serial number 15000. Over 6,200 machines were produced in the next two years. This machine has serial number 17536, which is marked in the center front. It has a metal tag screwed to the top that reads in part: TRADE COMPTOMETER MARK. There are ten patent dates on this tag.
label: Description
content: This machine came to the Smithsonian in 1981 from the collection of Esther S. and James C. Henderson, who ran an office equipment business in Corvallis, Washington.
label: Description
content: For a related adding machine section, see MA.323643.
label: Description
content: References:
label: Description
content: Felt & Tarrant, "Accession Journal ,"1991.3107.06.
label: Description
content: J. H. McCarthy, <I>American Digest of Business Machines</I>, 1924, Catalog Section, p. 71.
label: Location
content: Currently not on view
place: label: place made
content: United States: Illinois, Chicago
topic: label: Subject
content: Mathematics
setName: label: See more items in
content: Medicine and Science: Mathematics
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content: Adding Machines
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content: Science & Mathematics
creditLine: label: Credit Line
content: Gift of Esther H. and James C. Henderson
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1982.0234.01
label: maker number
content: 17536
label: catalog number
content: 1982.0234.01
label: accession number
content: 1982.0234
objectType: label: Object Name
content: adding machine
physicalDescription: label: Physical Description
content: plastic (overall material)
label: Physical Description
content: steel (overall material)
label: Physical Description
content: glass (overall material)
label: Physical Description
content: german silver (overall material)
label: Physical Description
content: wood (overall material)
label: Measurements
content: overall: 14.2 cm x 23.5 cm x 37 cm; 5 19/32 in x 9 1/4 in x 14 9/16 in