The museum will be open Fridays through Tuesdays 11:00 a.m.–4 p.m. beginning Sept. 25. Reserve your free timed-entry pass and review our latest visitor safety guidelines.

Telescopic Alidade

Telescopic Alidade

<< >>
Usage conditions apply
Downloads
Description
This alidade has a telescope with a level mounted above, and a vertical circle that is silvered, graduated to 30 minutes, and read by vernier to single minutes. The base has two perpendicular level vials. The U.S. Geological Survey transferred it to the Smithsonian in 1907, describing it as a "preliminary type" of alidade devised for the Survey about 1890.
Location
Currently not on view
Object Name
alidade (telescopic)
Measurements
base: 20 in; 50.8 cm
telescope: 10 1/4 in; 26.035 cm
overall: 8 9/16 in x 20 in x 4 in; 21.74875 cm x 50.8 cm x 10.16 cm
ID Number
PH.247913
catalog number
247913
accession number
47736
Credit Line
U.S. Geological Survey
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.

Comments

Add a comment about this object