Surveyor's Transit

Surveyor's Transit

<< >>
Usage conditions apply
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
See more items in
Medicine and Science: Physical Sciences
Measuring & Mapping
Surveying and Geodesy
Data Source
National Museum of American History
Nominate this object for photography.   

Our collection database is a work in progress. We may update this record based on further research and review. Learn more about our approach to sharing our collection online.

If you would like to know how you can use content on this page, see the Smithsonian's Terms of Use. If you need to request an image for publication or other use, please visit Rights and Reproductions.


Add a comment about this object