Darling, Brown & Sharpe Astronomical Linear Slide Rule
date: label: date made
content: 1887
name: label: patentee
content: Darling, Samuel
label: maker
content: Brown & Sharpe Manufacturing Company
notes: label: Description
content: This large mahogany linear astronomical slide rule is covered with strips of German silver. There are two slides, each of which have scales on both sides. Each slide has a knob near one end for moving it; these may be unscrewed and attached on the reverse side. One slide is marked COLLIMATION on one side and AZIMUTH on the other. The other slide is marked LEVEL AZIMUTH on one side and REFRACTION on the other. The base has four identical, unlabeled logarithmic scales, each of which runs from 1 to 10 twice (with a bit more at each end).
label: Description
content: On the center portion of the base, the instrument is marked Darling Brown & Sharpe Providence R.I. Darling, Brown & Sharpe did business under that name from 1866 to 1892. For additional company history, see 1977.0460.01. According to records of the United States Naval Observatory, this slide rule was purchased for $154.00 in December 1887. Few slide rules specifically for astronomy survive, so these large and expensive objects were probably not widely used. Compare to two late 19th-century rules held by the Powerhouse Museum, http://www.powerhousemuseum.com/collection/database/?irn=233017.
label: Description
content: Reference: Ledger of Instruments Purchased by the U.S. Naval Observatory, ca. 1845–1906, United States Naval Observatory, Washington, D.C.
label: Location
content: Currently not on view
place: label: place made
content: United States: Rhode Island, Providence
topic: label: Subject
content: Mathematics
label: Subject
content: Rule, Calculating
label: Subject
content: Astronomy
setName: label: See more items in
content: Medicine and Science: Mathematics
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content: Science & Mathematics
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content: Slide Rules
creditLine: label: Credit Line
content: Transfer from U.S. Naval Observatory
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1987.0693.01
label: catalog number
content: 328994
label: accession number
content: 1987.0693
objectType: label: Object Name
content: slide rule
physicalDescription: label: Physical Description
content: german silver (laminate material)
label: Physical Description
content: mahogany (overall material)
label: Measurements
content: overall: 6.9 cm x 112 cm x 15.4 cm; 2 23/32 in x 44 3/32 in x 6 1/16 in