Sextant
date: label: date made
content: 1810-1819
name: label: maker
content: Allen, John
notes: label: Description
content: The "J. Allan, Baltimore" inscription on this sextant is that of John Allen (b. 1786), an "optician and mathematical instrument maker" listed in Baltimore city directories from 1810 to 1819. He was the son of James Allen, a noted instrument maker in London. And he boasted: "As all Instruments sold by me are graduated by my father’s improved self-correcting engine, for which the Society of Arts voted him their Gold Medal, on the 19th of May, 1810–they are warranted and will be kept in repair one year, gratis."
label: Description
content: This sextant has a brass frame. The silvered scale is graduated every 20 minutes from -5° to +145° and read by vernier with tangent screw and magnifier to 30 seconds of arc.
label: Description
content: Ref: Deborah J. Warner, "American Octants and Sextants: The Early Years," <i>Rittenhouse</i> 3 (1989): 86-112, on 89.
label: Description
content: John Allen advertisement in the <i>American & Commercial Daily Advertiser</i> (June 12, 1816).
label: Location
content: Currently not on view
place: label: place made
content: United States: Maryland, Baltimore
setName: label: See more items in
content: Medicine and Science: Physical Sciences
label: See more items in
content: Navigation
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content: Measuring & Mapping
creditLine: label: Credit Line
content: College of the Holy Cross
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: PH.326932
label: accession number
content: 264083
label: catalog number
content: 326932
objectType: label: Object Name
content: sextant
physicalDescription: label: Measurements
content: radius: 7 in; 17.78 cm
label: Measurements
content: overall in box: 5 1/8 in x 12 3/4 in x 10 3/4 in; 13.0175 cm x 32.385 cm x 27.305 cm