Astronomical Transit Instrument
date: label: date made
content: ca 1865
name: label: maker
content: Pistor & Martins
notes: label: Description
content: This graduated circle is a key part of the large instrument that was designed for determining the positions of stars, produced by Pistor & Martins in Berlin, and installed at the U.S. Naval Observatory in Washington, D.C., in 1865.
label: Description
content: The circle measures 45.30 inches in diameter overall. The diameter of graduation is 43.40 inches. It is graduated to 2 minutes of arc, and would have been read by 4 microscope micrometers to 0.5 seconds of arc.
label: Description
content: Ref: <i>Instruments & Publications of the United States Naval Observatory</i> (1876), pp. 21-22.
label: Description
content: Elias Loomis, <i>An Introduction to Practical Astronomy</i> (1855), pp. 494-495, provides prices of meridian circles and transit instruments made by Pistor & Martins.
label: Location
content: Currently not on view
place: label: place made
content: Germany: Berlin, Berlin
topic: label: Subject
content: Astronomy
setName: label: See more items in
content: Medicine and Science: Physical Sciences
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content: Science & Mathematics
creditLine: label: Credit Line
content: U.S. Naval Observatory
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: PH.327717
label: accession number
content: 283654
label: catalog number
content: 327717
objectType: label: Object Name
content: astronomical transit instrument
physicalDescription: label: Measurements
content: overall: 115 cm x 4.5 cm; 45 9/32 in x 1 25/32 in