Experiments demonstrating an electrical effect in vibrating metals

In a previous communication some experiments were described by one of us which indicated the possibility that part of the energy of a vibrating wire gave rise to an E. M. F. in it, and so produced an alternating current strong enough to be audible in an ordinary telephone, and but little affected by the angle of the wire to the lines of the earth’s magnetic force. 2. Among other questions raised at the discussion of the paper was one whether the E. M. F. might not be due to a thermal effect at the soldered junctions of the vibrating wire. The effect of rusting the wire and also the possibility of mechanical transmission of the vibration to the telephone were also mentioned. To endeavour to throw further light on what appeared to be a rather obscure effect, the experiments have been continued, and have led to a further development of the matter.