An electrical prospecting method using equipotential lines or curves in prospecting for orebodies. In the parallel wire method, two bare copper wires about 3,000 ft (915 m) long, placed about 2,000 ft (610 m) or more apart, are used as electrodes. Current is supplied from the generator, and the electrodes are connected to the ground at 100 ft (30 2249 m) intervals by iron grounding pins. Equipotential lines are located by two electrodes or wooden rods, to one end of which are fastened metal spikes about 6 to 7 in (15 to 18 cm) long. The electrodes are connected by some 150 ft (46 m) of wire that runs down the rods to the spikes. If a head telephone is placed in the circuit, the absence of sound in the telephone indicates that the two electrodes are at the same potential. By this method, the equipotential lines can be traced.