Earth Inductor
Earth Inductor
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- Description
- As scientists found that even the best dip circles gave unreliable results, they began using earth inductors to determine magnetic dip. In 1912, the Department of Terrestrial Magnetism of the Carnegie Institution of Washington developed a new earth inductor for use at sea. It had three key elements: an improved gimbal stand, a means for rotating the coil without disturbing the gimbal rings, and a sensitive galvanometer.
- This example marked "D.T.M. C.I.W. E.I. N° 3" is the third Carnegie marine earth inductor. When the Carnegie closed its program in terrestrial magnetism, it was lent to the U.S. Coast and Geodetic Survey. The U.S. Geological Survey acquired it in 1973 when it took over the geomagnetic program of the federal government, and transferred it to the Smithsonian in 1982.
- Ref: J. A. Fleming, "Description of the C.I.W. Marine Earth
- Inductor," Terrestrial Magnetism 18 (1912): 39-45.
- C. W. Hewlett, "Report on the C.I.W. Marine Earth Inductor," Terrestrial Magnetism 18 (1912): 46-48.
- Location
- Currently not on view
- Object Name
- earth inductor
- Date made
- 1912
- maker
- Carnegie Institution of Washington. Department of Terrestrial Magnetism
- Place Made
- United States: District of Columbia, Washington
- Physical Description
- metal (overall material)
- Measurements
- overall: 9 1/2 in; 24.13 cm
- overall in case: 12 11/16 in x 9 3/8 in x 8 7/8 in; 32.22625 cm x 23.8125 cm x 22.5425 cm
- ID Number
- 1982.0671.05
- accession number
- 1982.0671
- catalog number
- 1982.0671.05
- Credit Line
- U.S. Department of the Interior, U.S. Geological Survey
- subject
- Science & Scientific Instruments
- Science & Scientific Instruments
- See more items in
- Medicine and Science: Physical Sciences
- Science & Mathematics
- Measuring & Mapping
- Data Source
- National Museum of American History
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