On methods whereby the radiation of electric waves may be mainly confined to certain directions, and whereby the receptivity of a receiver may be restricted to electric waves emanating from certain directions

Abstract

This Note relates to results observed when for the usual vertical antenna employed as radiator or absorber in wireless telegraph stations there is substituted a straight horizontal conductor placed at a comparatively small distance above the surface of the ground or water. When an insulated horizontal wire, AB, such as is shown in sketch 1, is connected at one end to a sphere of a spark gap, the other sphere of which is earthed, and sparks are caused to pass between the spheres, it will be noticed on investigating the space around such an oscillator that the radiations emitted reach a maximum in the vertical plane of the horizontal wire, AB, and proceed principally from the end, A, which is connected to the spark gap, whilst the radiation is nil , or reaches a minimum, in directions which are approximately 100° from the direction in which the maximum effect occurs.