Faraday described the space around a magnet to be filled with 'lines of magnetic force'. Similarly, the region around an electrified object may be considered to be filled with 'lines of electric force'. To Faraday, these lines existed as mechanical structures in the surrounding medium (the dielectric)  and could exert force on an object placed therein. Two typical electrostatic field structures are shown in Fig. 2.1. In figure (a), the field between a sphere or a cylinder and plane is sketched, and in figure(b), the field pattern on a bundle of four conductors used for transmission lines is shown, neglecting the effect of ground.