Abstract :
The paper describes an improved recorder for indicating the direction of arrival of transient impulses continuously throughout the day. The polar diagram of the receiver has a width of 20° and is unambiguous. The analysis of three years´ records shows that most of the atmospheric disturbance reaching a station in England arrives from the west or south-west, but that during summer afternoons sources to the east and southeast are productive together with storms of a purely local character. The disturbed azimuths appear closely related to the bearing of the great tropical thunderstorm centres, but the intensity of disturbance from each is dependent on the ionization conditions prevailing over the path to the receiver, at the time each region is productive. Curves are given from which the probable intensity of atmospheric in any direction at any time may be roughly determined.