Four electromagnetic propositions, with fluid mapper verification

A METHOD has been devised to give a visible representation of a magnetic or electrical field. Since reference can be made to another paper¹ in which fluid mappers have been described, a very brief description must suffice here. In Figure 1A, a thin and uniform flow space would be provided between the flat face of a slab and the lower surface of a piece of plate glass. A hole or well in the slab, where the conductor is simulated, provides fluid entry; thus it is a source. The iron is represented by a barrier. If the slab and plate were of infinite extent, and if the flow is kept to within the streamline range, fluid-flow lines would simulate magnetic equipotentials, and isopressure lines would simulate flux lines. If a finite slab is made large in all directions as compared with the distance from the source to the singular point S, a close agreement with the idealized case could be secured.