|This shows that that that distance the inductive action of C is entirely
exerted upon the interior of A, ... If C is made to touch the bottom of
A, all of its charge is communicated to A, ... and C, upon being
withdrawn, ... is found to be perfectly discharged." (From a letter written
by Michael Faraday to Richard Phillips, the editor of Phil. Mag.
on February 4, 1843. The diagram is from L. Pearce Williams, Michael
Faraday, A Biography (Simon and Schuster, New York, 1971), pg
And so introductory physics students have been studying the Faraday Ice Pail Experiment ever since, learning that in an electrically-conducting body, the charge resides on the surface.
Two almost identical ice pails at the top are from Colby College (left) and the University of Vermont (right). At the left below is an ice pail from Allegheny College, and the one at the right is in the Smithsonian Institution collection.
|| The ice pail at the left is in regular use in physics
lecture demonstrations at the University of Texas at Austin. The 1888 Queen
catalogue lists it for $8.00, including a proof plane. This example dates
from the early part of the twentieth century.
Variations on the ice pail demonstration arrived soon after
Faraday's letter. In 1855, George Francis's book, Electrical Experiments
discussed the Electric Well demonstration: "Place upon an electric stood,
a metal quart pot, mug, or some other conducting body, nearly of the same
form and dimension, then tie a short cork ball electroscope, that is two
cork balls suspended upon a linen thread, to a silken cord. Electrify the
mug, and hold the electroscope within it, when it will not be at all affected."