Robertson-Amsler Polar Planimeter

Description:

This chrome-plated instrument has a 5" pole arm with a small cylindrical weight at the end. The 7" tracer arm is adjustable and has an L-shaped tracer point, so that the point is offset from the arm. The carriage for adjusting the tracer arm holds the metal measuring wheel and vernier. The instrument has no registering dial. A point extending from the back of the carriage allows the user to turn the planimeter vertically and use the other end of the tracer point. Compare to MA.333766.

A wooden case covered with black leather is lined with light blue silk. The top of the case is marked: ME 4P5. A brass plate on top of the case is also marked: 4P5. The number is presumably an inventory number for the Department of Mechanical Engineering at

the University of Cincinnati, which donated the object. The instrument resembles the Robertson-Amsler planimeter shown in Hawkins's Indicator Catechism (New York, 1903), 132, and advertised in 1897 as an "averaging planimeter." See MA.302380.01 for instructions.

Hine & Robertson of New York City made steam-engine indicators and sold planimeters from the 1880s to 1897. The firm was then renamed James L. Robertson & Sons, and remained in operation until at least 1910. This device is smaller than the Hine-Robertson planimeter described by Olaus Henrici. For other planimeters sold by Robertson, see 1994.0356.01, MA.323703, MA.323704, and MA.324247.

According to the accession file, this object was received at the Smithsonian in 1981.

References: Advertisement for Robertson-Thompson Indicator, Power 17, no. 2 (February 1897): 25; John Walter, "More Information," The Engine Indicator, Canadian Museum of Making, http://www.archivingindustry.com/Indicator/sourceinfo.htm; Olaus Henrici, "On Planimeters," in Report of the Sixty-fourth Meeting of the British Association for the Advancement of Science (London, 1894), 515–516; "Hine and Robertson's Planimeter," The Electrician 26 (February 6, 1891): 432.

Date Made: ca 1900

Maker: James L. Robertson & Sons

Location: Currently not on view

Place Made: United States: New York, New York City

Subject: MathematicsEngineering

Subject:

See more items in: Medicine and Science: Mathematics, Planimeters, Science & Mathematics

Exhibition:

Exhibition Location:

Credit Line: Gift of University of Cincinnati Department of Mechanical Engineering

Data Source: National Museum of American History

Id Number: 1981.0301.01Accession Number: 1981.0301Catalog Number: 1981.0301.01

Object Name: planimeter

Physical Description: metal (overall material)wood (overall material)leather (overall material)cloth (overall material)Measurements: case: 3.7 cm x 20 cm x 6 cm; 1 15/32 in x 7 7/8 in x 2 3/8 in

Guid: http://n2t.net/ark:/65665/ng49ca746aa-b7b9-704b-e053-15f76fa0b4fa

Record Id: nmah_1214973

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