Gradienter
date: label: date made
content: 1887
name: label: associated institution
content: U.S. Department of the Interior. U.S. Geological Survey
notes: label: Description
content: This instrument is marked "No. 1 U.S.G.S." The horizontal circle and vertical arc are silvered, graduated to 30 minutes, and read by verniers to single minutes. A trough compass and level vial sit atop the telescope; a circular level sits on the horizontal circle. A micrometer attachment, sometimes termed a gradientor, measures the elevation of the telescope with great precision. The words "New November 15 87" are scratched on the underside of the horizontal plate.The U.S. Geological Survey transferred it to the Smithsonian in 1907.
label: Location
content: Currently not on view
setName: label: See more items in
content: Medicine and Science: Physical Sciences
label: See more items in
content: Surveying and Geodesy
label: See more items in
content: Measuring & Mapping
creditLine: label: Credit Line
content: U.S. Geological Survey
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: PH.247905
label: catalog number
content: 247905
label: accession number
content: 47736
objectType: label: Object Name
content: gradienter
physicalDescription: label: Measurements
content: horizontal circle: 3 1/2 in; 8.89 cm
label: Measurements
content: telescope: 8 1/2 in; 21.59 cm
label: Measurements
content: needle: 5 1/4 in; 13.335 cm
label: Measurements
content: overall in case: 6 1/8 in x 13 1/2 in x 9 3/4 in; 15.5575 cm x 34.29 cm x 24.765 cm