- This 30-inch transit was made by Troughton & Simms in London for the U. S. Coast Survey, probably in the late 1840s. Only the unusually short trunnions, telescope, small vertical circle, and micrometer eyepiece remain. The standards, graduated horizontal circle, and tripod base are missing.
- Ref: C. A. Schott, "Determination of the Astronomical Azimuth of a Direction," United States Coast Survey Annual Report (1866), Appendix No. 11.
- Currently not on view
- Object Name
- Geodetic Transit
- date made
- late 1840s
- Troughton and Simms
- place made
- United Kingdom: England, London
- telescope aperture: 2 3/8 in; 6.0325 cm
- telescope: 30 in; 76.2 cm
- vertical circle: 5 1/2 in; 13.97 cm
- trunions: 12 1/2 in; 31.75 cm
- overall: 5 3/4 in x 33 in x 10 in; 14.605 cm x 83.82 cm x 25.4 cm
- ID Number
- accession number
- catalog number
- Credit Line
- U.S. Coast and Geodetic Survey
- Data Source
- National Museum of American History
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