A simple illustration of the action of these ether waves is that of throwing a stone into a placid lake. A series of ripples is created which spread out in circles. Any small piece of wood which may be floating upon the surface will bob up and down in each consecutive ripple. This is the principle of every wireless transmission, be it dispatch, sound, heat or energy. The diference is only in the length of the wave and the velocity of its oscillation.
Technical World Magazine (October 1912), p. 148, "Marconi's Plans for the World"