- This dip circle was designed by Julius Hilgard of the U.S. Coast Survey, constructed by William Würdemann, and in use by 1860. The vertical circle is located outside the wood and glass box, silvered, graduated to 15 minutes, and read by opposite verniers with magnifiers to 30 seconds. It supports two telescopes which are used to take sights on small holes pierced through the ends of the needle. The horizontal circle is silvered, graduated to 30 minutes and read by vernier to single minutes. The inscriptions read "Wm Würdemann, Washington, D.C." and "U.S.C.S. No. 10."
- Ref: "Results of Magnetical Observations Made at Eastport, Maine, Between 1860 and 1864, for the United States Coast Survey," Report of the Superintendent of the United States Coast Survey During the Year 1865, Appendix 18.
- Currently not on view
- Object Name
- dip circle
- Date made
- ca 1860
- Wurdemann, William W.
- Place Made
- United States: District of Columbia, Washington
- Physical Description
- metal (overall material)
- vertical circle: 6 1/2 in; 16.51 cm
- overall: 14 3/4 in x 12 13/16 in x 8 1/16 in; 37.465 cm x 32.54375 cm x 20.47875 cm
- ID Number
- catalog number
- accession number
- Credit Line
- U.S. Coast & Geodetic Survey
- Science & Scientific Instruments
- Data Source
- National Museum of American History
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