Variously shaped and spaced conductors are placed in a bath of mineral oil. Grass seed is sprinkled on top of the oil. A high potential from a small Van de Graff generator is placed on the conductors. The field is mapped by the alignment of the grass s eed floating on the oil. Oil Bath tank is placed on an overhead for classroom presentation.
Option 2 A self contained system that has various configurations of conductors placed in it. The field is obtained from a Zerostat piezoelectric gun.