Point discharge from natural and artificial points (Pt. II)

Abstract

Abstract Measurements have been made of the point‐discharge current through an artificial point at about tree‐top height, the potential gradient at the ground nearby and the wind speed. The results are similar in form to those for an isolated point at greater height and do not show the square‐law relation between current and potential gradient that has previously been found when wind‐speed has not been taken into account. The current flowing down a living tree has also been measured and obeys a similar relation with potential gradient.