More than three dozen books and countless magazine articles have already been written upon wireless or ether wave telegraphy. Hundreds have and thousands are contributing to our knowledge of ether wave phenomena. If the names of all who have said or done something to render stable the foundations of this idea of a universal ether, whose undulations account for the phenomena of heat, light, and electricity, were to be mentioned, the list would contain nearly all the important workers in the field of physics for the last century. XXVI ELECTRIC CURRENTS CANNOT BE CONFINED TO WIRES Harold said that if electricity was so much like light that it could go without wires he thought light ought to be enough like electricity to be conducted by wires on occasions. I told him that I had no hope of being able to confine light to a wire; indeed, if the Science Club would give me an opportunity I would show them that even when electricity follows the general direction of a wire its influence is not confined to the wire. As a result of this bid I received an invitation to address an open meeting of the Science Club. [Illustration: Fig. 198] In my first experiment on that occasion I took a one-pound spool of No. 24 cotton-covered copper wire and crowded the hole in the spool full of wire nails _A_ (Fig. 198). I disconnected the wires from an electric drop lamp and connected them to _b_ and _c_, the ends of the wire from the spool. Our electric lighting circuit was what is called the _alternating current_. I also had a second spool, _B_, precisely like the first. The wires from this were connected to a miniature lamp, _L_, such as is used at the switchboard of a telephone exchange. We then screwed the drop-light plug into the chandelier and turned on the electric current. I brought spool _B_ with the miniature lamp near to spool _A_, as shown in Fig. 199, and when it was within a distance of about two inches the little lamp lighted up to full brilliancy, thus showing that while the electric current is passing in the wire of spool _A_ its influence is not confined to the wire, but exhibits itself in the region outside of the wire. To illustrate still further this fact we substituted an electric bell in the place of the lamp _L_, and when the spool _B_ was brought near to _A_ the bell rang. But the most striking illustration was obtained when a telephone receiver was put in the place of _L_. With this held to the ear while the spool _B_ was brought toward _A_ a humming sound could be heard when _B_ was about a foot distant from _A_. This sound grew rapidly louder as _B_ approached _A_, until, when the spool _B_ rested upon the spool _A_, a sound like the peal of a pipe organ was heard all over the apartment. The tone was very nearly that of the key on the piano which is two octaves below middle _C_. I unscrewed the cap on the large end of the telephone receiver, took it off, and moved the thin iron diaphragm to