Book Excerpt: ...n, so it seems that; in all branches of industry alternating currents--electric wave motion--will have the sway.One reason, perhaps, why this branch of science is being so rapidly developed is to be found in the interest 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..