Carrington's Patent Rolling Parallel Rule

Description:

A 14" trapezoidal mahogany frame with metal end pieces covers two mahogany rollers that rotate on metal shafts. A paper label is marked: CARRINGTON'S PATENT PARALLEL RULER, FOR COUNTING HOUSES, &C. The label is decorated with an eagle over a shield with arrows in its claws. The eagle's beak holds a banner marked: E PLURIBUS UNUM.

On April 14, 1832, James Carrington of Wallingford, Conn., patented a parallel ruler that was later manufactured by William Hill of Wallingford. The rollers were raised in order to prevent ink from smearing as the ruler was moved across a drawing. In 1849 the U.S. House of Representatives ordered six dozen of the rulers from R. Farnham, a stationer in Washington, D.C., for $2.30 per dozen. This suggests the rules were used relatively widely for a significant period of time. Before he built a dam and factory in Wallingford around 1830, Carrington was a supervisor and inspector at the Harpers Ferry and Springfield armories.

References: "American Patents," The Repertory of Patent Inventions 15 (1833): 24; "Power, Factories, Invention," in Centennial of Meriden: June 10–16, 1906 (Meriden, Conn.: Journal Publishing Co., 1906), 245; U.S. House of Representatives, Contracts for Stationery, 31st Congress, 1st Session, Miscellaneous, No. 16, December 31, 1849 (Washington, D.C., 1850), 16–17; Hiram Williams Beckwith, History of Montgomery County, Together With Historic Notes on the Wabash Valley (Chicago, 1881), 246; Merritt Roe Smith, Harpers Ferry Armory and the New Technology (Cornell: University Press, 1977), 203, 207, 229.

Date Made: mid 19th century

Patentee: Carrington, James

Location: Currently not on view

Place Made: United States: Connecticut, Wallingford

Subject: MathematicsDrafting, EngineeringBusiness

Subject:

See more items in: Medicine and Science: Mathematics, Science & Mathematics, Parallel Rules

Exhibition:

Exhibition Location:

Credit Line: Warshaw Collection of Business Americana

Data Source: National Museum of American History

Id Number: MA.293320.2818Accession Number: 293320Catalog Number: 293320.2818

Object Name: parallel rule

Physical Description: metal (overall material)wood (overall material)Measurements: overall: 2.2 cm x 35.6 cm x 4.9 cm; 7/8 in x 14 1/32 in x 1 15/16 in

Guid: http://n2t.net/ark:/65665/ng49ca746a5-16d9-704b-e053-15f76fa0b4fa

Record Id: nmah_690257

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