Ford Instrument Company Ball & Disc Integrator

Object Details

Description

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. The object shows modifications and refinements made by the American inventor Hannibal Ford. It consists of a metal mechanism held in an aluminum frame painted white that is attached to a black bakelite base. The mechanism includes two (rather than just one) hardened steel balls that roll against one another. The bottom ball is turned by a disc on the bottom driven by an input gear. The top ball drives a roller.

A metal tag on the front of the base reads: 2 ½ Inch (/) BALL AND DISK (/) INTEGRATOR (/) Presented by (/) FORD INSTRUMENT COMPANY (/) DIVISION OF SPERRY RAND CORPORATION.

Ford's integrators were used in devices for aiming guns on ships of the U.S. Navy from about 1915 into the 1940s. The company merged with Sperry Corporation and, in 1955, became a subdivision of the newly established Sperry Rand Corporation. This object dates from after the establishment of Sperry Rand and before the donation of the object to the Smithsonian in 1961. A leaflet describes “Ford Precision DBR Integrators.” Here the acronym DBR is defined to mean “DIsk-Balls and Roller Integrator.”

Compare 1982.0751.06 and 1979.0751.36.

References:

“Ford Precision DBR Integrators,” no date.

Accession file.

A.B. Clymer, "The Mechanical Analog Computers of Hannibal Ford and William Newell," Annals of the History of Computing, 15, #2, 1993, 19-34.

Location

Currently not on view

Credit Line

Gift of Ford Instrument Company

Data Source

National Museum of American History

date made

ca 1960

ID Number

MA.319517

catalog number

319517

accession number

239018

maker

Ford Instrument Company

Object Name

integrator

Measurements

overall: 11.5 cm x 30.8 cm x 25.6 cm; 4 17/32 in x 12 1/8 in x 10 3/32 in

place made

United States: New York, Queens, Long Island City

See more items in

Medicine and Science: Mathematics

Mechanical Integrators and Analyzers

Subject

Mathematics

Record ID

nmah_1214999

Usage

CC0

GUID

https://n2t.net/ark:/65665/ng49ca746aa-947c-704b-e053-15f76fa0b4fa