rest which is attached to its
experimental study. We wind a simple ring of iron with coils; we
establish the connections to the generator, and with wonder and
delight we note the effects of strange forces which we bring into
play, which allow us to transform, to transmit and direct energy at
will. We arrange the circuits properly, and we see the mass of iron
and wires behave as though it were endowed with life, spinning a heavy
armature, through invisible connections, with great speed and
power--with the energy possibly conveyed from a great distance. We
observe how the energy of an alternating current traversing the wire
manifests itself--not so much in the wire as in the surrounding
space--in the most surprising manner, taking the forms of heat, light,
mechanical energy, and, most surprising of all, even chemical
affinity. All these observations fascinate us, and fill us with an
intense desire to know more about the nature of these phenomena. Each
day we go to our work in the hope of discovering,--in the hope that
some one, no matter who, may find a solution of one of the pending
great problems,--and each succeeding day we return to our task with
renewed ardor; and even if we _are_ unsuccessful, our work has not
been in vain, for in these strivings, in these efforts, we have found
hours of untold pleasure, and we have directed our energies to the
benefit of mankind.

We may take--at random, if you choose--any of the many experiments
which may be performed with alternating currents; a few of which
only, and by no means the most striking, form the subject of this
evening's demonstration: they are all equally interesting, equally
inciting to thought.

Here is a simple glass tube from which the air has been partially
exhausted. I take hold of it; I bring my body in contact with a wire
conveying alternating currents of high potential, and the tube in my
hand is brilliantly lighted. In whatever position I may put it,
wherever I may move it in space, as far as I can reach, its soft,
pleasing light persists with undiminished brightness.

Here is an exhausted bulb suspended from a single wire. Standing on an
insulated support. I grasp it, and a platinum button mounted in it is
brought to vivid incandescence.

Here, attached to a leading wire, is another bulb, which, as I touch
its metallic socket, is filled with magnificent colors of
phosphorescent light.

Here still another, which by my fingers' touch casts a shadow--t