es.

A very interesting effect was noticed one night when there was a bright
aurora display. There was a continuous current through the wires,
accompanied with sounds which increased in intensity as the bright
streamers passed by. This will probably lead to some important results
in science.

In all probability the telephone is as much in its infancy as was
ordinary telegraphy in 1840. Since that time the sciences of electricity
and magnetism have had the most of their growth, and telegraphy has kept
pace with the advancing knowledge until its commercial importance is
second to no other agency. Very many important principles that are
invaluable in telegraphy to-day were wholly unknown in 1840; but it may
here be noted that in the telephone, as it now is, there is not a single
principle that was not well enough known in 1840. This will be apparent
to one who follows out the phenomena from the sender to the receiver.
First, the sound in air causing a corresponding movement in a solid
body, iron. This iron, acting inductively upon a magnet, originates
magneto-electric currents in a wire helix about it; and these travel to
another helix, and, re-acting upon the magnet in it, have
electro-magnetic effects, and increase and decrease the strength of the
magnet; and this variable magnetism affects the plate of iron in front
of that magnet, and makes it to vibrate in a corresponding manner, and
thus to restore to the air in one place the vibrations absorbed from the
air in another place. To some it may seem strange that a simple thing as
the telephone is, involving nothing but principles familiar enough to
every one interested in physical science, should have waited nearly
forty years to be invented. The reason is probably this: Men of science,
as a rule, do not feel called upon to apply the principles which they
may discover. They are content to be _discovering_, not _inventing_.
Now, the schools of the country ought to make the youth quite familiar
with the general principles of physical science, that the inventive
ones--and there are many such--may apply them intelligently. Mechanism
is all that stands between us and aerial navigation; all that is
necessary to reproduce human speech in writing; and all that is needed
to realize completely the prophetic picture of the "Graphic," of the
orator who shall at the same instant address an audience in every city
in the world.

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