Planimeter, Parallel Bar Type
date: label: date made
content: late 19th century
notes: label: Description
content: This instrument consists of 12 flat parallel metal rods screwed at each end to somewhat wider parallel rods. The rods are equally spaced, except for the first and last, which are only half as far apart as the others. The device was designed for locating ordinates on a steam-engine indicator diagram that should be measured and multiplied by the length of the diagram to give a rough estimate of the area under the curve. This object was owned by the renowned American designer of steam engines, Erasmus Darwin Leavitt Jr. (1836–1916), and donated by his granddaughter, Margaret van D. Rice.
label: Description
content: The instrument was received at the museum in 1976.
label: Description
content: Reference: N. Hawkins, <i>Hawkins' Indicator Catechism</i> (New York: Theo. Audel & Co., 1903), 107–110.
label: Location
content: Currently not on view
topic: label: Subject
content: Mathematics
label: Subject
content: Engineering
setName: label: See more items in
content: Medicine and Science: Mathematics
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content: Planimeters
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content: Science & Mathematics
creditLine: label: Credit Line
content: Gift of Margaret van D. Rice
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1977.0460.11
label: catalog number
content: 336082
label: accession number
content: 1977.0460
objectType: label: Object Name
content: planimeter, rectangular
physicalDescription: label: Physical Description
content: metal (overall material)
label: Measurements
content: overall: .3 cm x 16.1 cm x 13.5 cm; 1/8 in x 6 11/32 in x 5 5/16 in