- 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.
- 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.
- Ref: W. & L. E. Gurley, Light Weight Transits (Troy, N.Y., 1929).
- Currently not on view
- Object Name
- surveyor's transit
- date made
- W. & L. E. Gurley
- place made
- United States: New York, Troy
- overall: 7 3/8 in; 18.7325 cm; wt: 9.5 lbs
- horizontal graduated circle: 6 1/4 in; 15.875 cm
- vertical circle: 5 in; 12.7 cm
- telescope: 10 in; 25.4 cm
- hanging level: 6 in; 15.24 cm
- 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
- ID Number
- accession number
- catalog number
- Data Source
- National Museum of American History
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