Surveyor's Transit
date: label: date made
content: 1930
name: label: maker
content: W. & L. E. Gurley
notes: label: Description
content: Surveyors who carry instruments long distances, often over difficult terrain, are always concerned about weight. W. & L. E. Gurley made their first lightweight instrument—an aluminum transit—in 1876. But the prohibitive cost of aluminum kept them from manufacturing instruments of this material. Following World War I, Gurley introduced a line of instruments made of an aluminum alloy named Lynite. This transit is of that sort. Gurley termed it a Lightweight Engineers' Transit and sold it, with tripod, for $275. The inscription reads "W. & L. E. GURLEY TROY N.Y., U.S.A. 3028." The serial number indicates that it was the 28th instrument that Gurley made in 1930. The horizontal and vertical circles are silvered, graduated every 30 minutes of arc, and read by opposite verniers to single minutes.
label: Description
content: One standard is marked "PATENT 1731848." The reference is to the patent granted to W. L. Egy on October 15, 1929, and assigned to Gurley. This patent described a graduated circle or arc for surveying instruments made of an aluminum alloy.
label: Description
content: Ref: W. & L. E. Gurley, <i>Light Weight Transits</i> (Troy, N.Y., 1929).
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: W. & L. E. Gurley. Light Weight Transits
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1986.0091.01
label: accession number
content: 1986.0091
label: catalog number
content: 1986.0091.01
objectType: label: Object Name
content: surveyor's transit
physicalDescription: label: Measurements
content: overall: 7 3/8 in; 18.7325 cm; wt: 9.5 lbs
label: Measurements
content: horizontal graduated circle: 6 1/4 in; 15.875 cm
label: Measurements
content: vertical circle: 5 in; 12.7 cm
label: Measurements
content: telescope: 10 in; 25.4 cm
label: Measurements
content: hanging level: 6 in; 15.24 cm
label: Measurements
content: overall: 13 3/4 in x 7 3/8 in x 10 1/4 in; 34.925 cm x 18.7325 cm x 26.035 cm