Lightning phenomena in electric circuits

1. Originally lightning denoted electric discharges between clouds or between cloud and ground, and, when applied to an electric circuit, the results of such a discharge striking the line. Later it was found that during atmospheric disturbances, such as passing thunder storms, disturbances occurred in electric circuits even without the discharges striking the line. These disturbances — caused by induction — were also classed as “lightning,” and applied to electric circuits, lightning then came to mean all the effects of atmospheric electricity.