Referring to Fig. 3, let C represent a capacity connected to the ground MN through the adjustable inductance I. If means be employed to cause the residual charge of this capacity to oscillate, it will, in turn, cause a wave-like motion of the electromagnetic forces of the earth similar to the wave motion in water.
If either the capacity or inductance is increased, the vibrations will be slower, and the wave length will be
Fig. 3.—Theory of Wireless Telegraphy.
greater. The waves thus generated are propagated through the earth’s forces in ever-increasing circles, exactly as in the case of the water waves,
C' in Fig. 3 represents the receiving capacity connected to the ground through the inductance I', in the same manner as at the sending station. This capacity, of course, also contains a residual charge which is dormant under normal conditions, but as the wave front glides by the station, the rising and falling of the waves will impart a slight oscillatory motion to the residual charge.
