This work describes an electric discharge in air at atmospheric pressure between a thin wire and a cathode with an elliptical cross section. The short axis of the ellipse was so small that the cathode surface facing the thin anode wire could be approximated by a plane. The cathode was split in two parts with the split parallel to the wire. When this discharge was exposed to a wind blowing perpendicular to the wire and parallel to the plane, it was found that the average displacement of the positive ions was directly proportional to the free‐stream velocity. The actual displacement could be determined by moving the wire to an upstream position such that the two parts of the cathode carried the same current. The measurements were made in a wind tunnel with velocities from about 1 to 18 m/sec.