When capacitance-bridge measurements in the audio-frequency range are made on most dielectrics, it will be found that, as the measuring frequency is carried below 1 kc, both capacitance and dissipation factor begin to increase. Even at a frequency of 10 c, which is about as low as bridge measurements are carried, both capacitance and dissipation factor are increasing at an undiminished rate. Now that frequencies as low as 0.01 c are being used with capacitors, it becomes desirable to be able to predict the maximum values of capacitance and dissipation factor and the frequency at which the latter has its maximum.