Surveyor's Vernier Compass
date: label: date made
content: 1807-1817
name: label: maker
content: Potts, William Lukens
notes: label: Description
content: William Lukens Potts (1771-1854) worked with Benjamin Rittenhouse in the years 1796-1798, making plain and vernier compasses for surveyors. In 1800, now in business on his own, he advertised "surveying instruments of all kinds, and Rittenhouse' Circumferentors, with each a nounes and spirit level compleat." "Nounes" here refers to a nonius, a term sometimes used in place of vernier.
label: Description
content: This example marked "W.L. POTTS Bucks Penna." was made between 1807, when Potts bought land in Bucks County, Pa., and 1817, when he moved to Philadelphia. The variation arc on the south arm extends 15 degrees either way; the "folded" vernier is moved by rack and pinion, and reads to 5 minutes. There is a spirit level on the north arm. A copy of Thomas Whitney's 1814 discussion of "The Variation of the Compass" is pasted into the inside cover of the wooden box.
label: Location
content: Currently not on view
place: label: place made
content: United States: Pennsylvania, Bucks county
setName: label: See more items in
content: Medicine and Science: Physical Sciences
label: See more items in
content: Surveying and Geodesy
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content: Measuring & Mapping
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1985.0468.01
label: accession number
content: 1985.0468
label: catalog number
content: 1985.0468.01
objectType: label: Object Name
content: Surveyor's Vernier Compass
label: Object Name
content: surveyor's vernier compass
physicalDescription: label: Measurements
content: overall length: 14 1/4 in; 36.195 cm
label: Measurements
content: needle: 5 in; 12.7 cm
label: Measurements
content: overall in case: 3 13/16 in x 14 1/2 in x 7 3/8 in; 9.68375 cm x 36.83 cm x 18.7325 cm