The determination of resonant frequencies and decay factors

Simple resonance curves plotted vectorically are approximately circular in form. The paper shows how the circle can be derived from the ordinary resonance curve by a simple graphical construction, and how from the derived circle and the original resonance curve a straight line can be drawn from which the resonance frequency and the damping are at once determined. The constructions developed are explained by their application to telephone-receiver impedances and to electrical circuits.