Faraday's Net.
An apparatus for showing that the electric charge resides on the
surface. It consists of a net, conical in shape and rather deep, to
whose apex two threads, one on each side, are attached. Its mouth is
fastened to a vertical ring and the whole is mounted on an insulating
support.
It is pulled out to its full extent and is electrified. No charge can be
detected inside it. By pulling one of the threads it is turned with the
other side out. Now all the charge is found on the outside just as
before, except that it is of course on the former inside surface of the
bag. The interior shows no charge.
Faraday's Transformer.
The first transformer. It was made by Michael Faraday. It was a ring of
soft iron 7/8 inch thick, and 6 inches in external diameter. It was
wound with bare wire, calico being used to prevent contact of the wire
with the ring and of the layers of wire with each other, while twine was
wound between the convolutions to prevent the wires from touching.
Seventy-two feet of copper wire, 1/20 inch diameter, were wound in three
superimposed coils, covering about one-half of the ring. On the other
half sixty feet of copper wire were wound in two superimposed coils.
Faraday connected his coils in different ways and used a galvanometer to
measure the current produced by making and breaking one of the circuits
used as a primary.
The coil is of historic interest.
Faraday's Voltameter.
A voltameter, in which the coulombs of current are measured by the
volume of the gas evolved from acidulated water. (See Voltameter, Gas.)
Faradic. adj.
Referring to induced currents, produced from induction coils. As Faraday
was the original investigator of the phenomena of electro-magnetic
induction, the secondary or induced electro-magnetic currents and their
phenomena and apparatus are often qualified by the adjective Faradic,
especially in electro-therapeutics. A series of alternating
electrostatic discharges, as from an influence machine (Holtz), are
sometimes called Franklinic currents. They are virtually Faradic, except
as regards their production.