Planimeter, Parallel Bar Type
Planimeter, Parallel Bar Type
Usage conditions apply
- Description
- 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.
- The instrument was received at the museum in 1976.
- Reference: N. Hawkins, Hawkins' Indicator Catechism (New York: Theo. Audel & Co., 1903), 107–110.
- Location
- Currently not on view
- Object Name
- planimeter, rectangular
- date made
- late 19th century
- Physical Description
- metal (overall material)
- Measurements
- overall:.3 cm x 16.1 cm x 13.5 cm; 1/8 in x 6 11/32 in x 5 5/16 in
- ID Number
- 1977.0460.11
- catalog number
- 336082
- accession number
- 1977.0460
- Credit Line
- Gift of Margaret van D. Rice
- subject
- Mathematics
- Engineering
- See more items in
- Medicine and Science: Mathematics
- Planimeters
- Science & Mathematics
- Data Source
- National Museum of American History
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