- This is one of eight dip circles that Edward Kahler made for the American expeditions sent to observe the transit of Venus across the face of the sun in 1874. It is marked "106." The vertical circle is graduated to 20 minutes. The horizontal circle is graduated to 30 minutes and read by vernier to single minutes. Both are silvered.
- Ref: Steve Dick, Sky and Ocean Joined (Cambridge, 2002), p. 250.
- Currently not on view
- Object Name
- Dip Circle
- Date made
- ca 1874
- Place Made
- United States: District of Columbia, Washington
- Physical Description
- wood (overall material)
- metal (overall material)
- vertical circle: 6 in; 15.24 cm
- horizontal circle: 4 1/2 in; 11.43 cm
- overall in case: 11 1/8 in x 11 in x 11 3/16 in; 28.2575 cm x 27.94 cm x 28.41625 cm
- ID Number
- catalog number
- accession number
- Credit Line
- U.S. Department of Defense, Dept. of the Navy, U.S. Naval Observatory
- Science & Scientific Instruments
- Data Source
- National Museum of American History
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