Surveyor's Transit
name: label: maker
content: Phelps & Gurley
notes: label: Description
content: This is an example of instrument makers feeling their way towards a good design, but not quite getting it right. It is marked "Phelps & Gurley" and "Troy, N.Y." and dates from the period 1845-1851 when Jonas Phelps and William Gurley were in business together. Several elements of its design originated with Oscar Hanks, the mathematical instrument maker with whom Phelps and Gurley both apprenticed. W. & L. E. Gurley made a similar instrument that they called a Vernier Transit Compass.
label: Description
content: The variation arc at the south side of the compass extends 20 degrees either way; the vernier reads to 2 minutes. There are level vials at North and West. The small vertical circle is read by vernier to 10 minutes.
label: Description
content: William H. Skerritt, <i>Catalog of the Charles E. Smart Collection of Antique Surveying Instruments</i> (Troy, N.Y., 1996), p. 29.
label: Location
content: Currently not on view
place: label: place made
content: United States: New York, Troy
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
publisher: label: Related Publication
content: Skerritt, William H.. Catalog of the Charles E. Smart Collection of Antique Surveying Instruments
creditLine: label: Credit Line
content: Leland C. Ball
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: PH.315412
label: accession number
content: 170660
label: catalog number
content: 315412
objectType: label: Object Name
content: transit instrument
label: Object Name
content: surveyor's transit
physicalDescription: label: Measurements
content: overall: 7 in; 17.78 cm
label: Measurements
content: needle: 5 in; 12.7 cm
label: Measurements
content: vertical circle: 3 1/2 in; 8.89 cm
label: Measurements
content: telescope: 9 3/4 in; 24.765 cm
label: Measurements
content: overall: 11 1/8 in x 8 3/4 in x 9 3/4 in; 28.2575 cm x 22.225 cm x 24.765 cm