Analog Computing Component - Integrator (Four-Inch Disc)
date: label: date made
content: ca 1918-1955
name: label: maker
content: Ford Instrument Company
notes: label: Description
content: Instruments for finding the area bounded by curved lines (integrators) date from the nineteenth century. This twentieth century example is based on a mechanism invented by British engineer James Thomson and used by his brother William (later Lord Kelvin) in constructing the first harmonic analyzer in 1876. As K.C. Epstein has recently shown, the American inventor Hannibal Ford improved the design, following ideas developed by Britons Pollen and Isherwood for the British Navy in the early twentieth century.
label: Description
content: The integrator consists of a mechanism of hardened steel held in a metal frame. A disc at the bottom is linked by two adjacent balls to a rotating shaft at the top – there is a gear at the end of the shaft. Each of the balls has four vertical rollers on it. Rotating a horizontal gear at the front rolls the carriage for the balls crosswise.
label: Description
content: A mark etched into the front edge of the base of the frame reads: U.S. NO. 772.
label: Description
content: Ford's integrators were used by the U. S. Navy in devices for aiming guns on ships. They continued in use after Ford Instrument was acquired by Sperry in 1955. The precise date of this integrator is not known, although it most probably is from after 1930.
label: Description
content: References:
label: Description
content: A.B. Clymer, "The Mechanical Analog Computers of Hannibal Ford and William Newell," <I>Annals of the History of Computing</I>, 15, #2, 1993, 19-34.
label: Description
content: K.C. Epstein, <I>Analog Superpowers: How Twentieth-Century Technology Theft Built the National Security State<I>, Chicago: University of Chicago Press, 2024.
label: Location
content: Currently not on view
place: label: place made
content: United States: New York, Queens, Long Island City
topic: label: Subject
content: Mathematics
setName: label: See more items in
content: Medicine and Science: Mathematics
label: See more items in
content: Mechanical Integrators and Analyzers
creditLine: label: Credit Line
content: Ford Instrument Company, Division of Sperry Rand Corporation
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1982.0751.07
label: catalog number
content: 1982.0751.07
label: accession number
content: 1982.0751
objectType: label: Object Name
content: analog computing component
physicalDescription: label: Physical Description
content: aluminum (frame material)
label: Physical Description
content: steel (mechanism material)
label: Measurements
content: overall: 7.8 cm x 18.3 cm x 12.3 cm; 3 1/16 in x 7 7/32 in x 4 27/32 in