Faraday's Ring or Hysteresis Coil

Faraday's Ring or Hysteresis Coil

<< >>
Usage conditions apply
Here, a circular coil and three pairs of binding posts are mounted on a wooden base marked “WOOD / O.D. 100 / I.D. 71” while a metal bar is marked “WM GAERTNER & CO. / CHICAGO.” L. E. Knott called this small instrument a Faraday’s Ring and Demonstration Transformer, describing it as a simple apparatus “designed for study of the principles and laws involved in self and secondary induction.” The Chicago Apparatus Co. called it a “Hysteresis Coil. Designed to meet the requirements of Experiment No. 15 in Millikan and Mills, ‘Electricity, Sound and Light.’”
Ref: Robert Andrews Millikan and John Mills, A Short University Course in Electricity, Sound and Light (Boston, 1908), pp. 164-165.
Wm. Gaertner Co. Catalog (Chicago, 1929), p. 2.
L. E. Knott Apparatus Co., Catalogue of Physical Instruments (Boston, 1912), p. 466.
Chicago Apparatus Co., Physical Instruments, Apparatus, and Supplies (Chicago, ca. 1931), p. 239.
Currently not on view
Object Name
Faraday’s ring or hysteresis coil
Gaertner Scientific Corporation
place made
United States: Illinois, Chicago
Physical Description
wood; metal (overall material)
overall: 1 3/4 in x 7 1/2 in; 4.445 cm x 19.05 cm
ID Number
catalog number
accession number
See more items in
Medicine and Science: Physical Sciences
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.


Add a comment about this object