Variometer
name: label: maker
content: Otto Toepfer & Sohn
notes: label: Description
content: This variometer, which measures slight changes in magnetic declination, is based on a design developed by J. F. A. M. Eschenhagen, Director of the Prussian Magnetic Observatory at Potsdam. An inscription on this example reads "Otto Toepfer & Sohn Potsdam XIII." The U.S. Coast and Geodetic Survey obtained several instruments of this sort from Toepfer around 1901 and kept them in use for many years. The U.S. Geological Survey acquired this example in 1973 when it assumed responsibility for the geomagnetic program of the federal government, and transferred it to the Smithsonian in 1982.
label: Description
content: Ref: M. Eschenhagen, "Magnetic Intensity Variometers," <i>Terrestrial Magnetism</i> 5 (1900): 59-62.
label: Description
content: Otto Toepfer & Sohn, <i>Neue transportable Feinregistrir-Einrichtung für Erdmagnetismus</i> (Potsdam, 1903).
label: Description
content: Daniel Hazard, <i>Results of Observations Made at the Coast and Geodetic Survey Magnetic Observatory at Baldwin, Kansas, 1901-1904</i> (Washington, D.C., 1909), pp. 10-11.
label: Location
content: Currently not on view
place: label: Place Made
content: Germany: Brandenburg, Potsdam
topic: label: Subject
content: Science & Scientific Instruments
label: Subject
content: Science & Scientific Instruments
setName: label: See more items in
content: Medicine and Science: Physical Sciences
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content: Science & Mathematics
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content: Measuring & Mapping
creditLine: label: Credit Line
content: U.S. Department of the Interior, U.S. Geological Survey
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1982.0671.12b
label: accession number
content: 1982.0671
label: catalog number
content: 1982.0671.12b
objectType: label: Object Name
content: variometer
physicalDescription: label: Physical Description
content: metal (overall material)
label: Measurements
content: overall: 19 1/2 in; 49.53 cm
label: Measurements
content: overall: 19 5/8 in x 6 7/8 in x 6 3/8 in; 49.8475 cm x 17.4625 cm x 16.1925 cm