ection on making the circuit, and in the opposite direction on
breaking it, he establishes the fact that the current induced on making
flows in the opposite direction to the inducing current, and that
induced on breaking flows in the same direction as the inducing current.

Having thus established the fact of current induction, he makes the step
of substituting magnets for active circuits; a simple step in the light
of our present knowledge, but a giant stride at that time. Remembering
that current induction, or, as he called it, voltaic current induction,
takes place only while some effect produced by the current is either
increasing or decreasing, he moves coils of insulated wire towards or
from magnet poles, or magnet poles towards or from coils of wire, and
shows that electric currents are generated in the coils while either the
coils or the magnets are in motion, but cease to be produced as soon as
the motion ceases. Moreover, these magnetically induced currents differ
in no respects from other currents,--for example, those produced by the
voltaic pile,--since, like the latter, they produce sparks, magnetize
bars of steel, or deflect the needle of a galvanometer. In this manner
Faraday solved the great problem. He had produced electricity directly
from magnetism!

With, perhaps, the single exception of the discovery by Oersted, in
1820, of the invariable relation existing between an electric current
and magnetism, this discovery of Faraday may be justly regarded as the
greatest in this domain of physical science. These two master minds in
scientific research wonderfully complemented each other. Oersted showed
that an electric current is invariably attended by magnetic effects;
Faraday showed that magnetic changes are invariably attended by electric
currents. Before these discoveries, electricity and magnetism were
necessarily regarded as separate branches of physical science, and were
studied apart as separate phenomena. Now, however, they must be regarded
as co-existing phenomena. The ignorance of the scientific world had
unwittingly divorced what nature had joined together.

In view of the great importance of Faraday's discovery, we shall be
justified in inquiring, though somewhat briefly, into some of the
apparatus employed in this historic research. Note its extreme
simplicity. In one of his first successful experiments he wraps a coil
of insulated wire around the soft iron bar that forms the armature or
keep