Plot of the potential generated at various distances from the stimulated non-uniform axon described equations (D.1) and (D.2) as a function of time for electrodes with varying distances from the axon. The recording electrode is located at the point z = 25 mm. In this graph, the abscissa is the location of the stimulator as it moves along the axon. The downward arrow denotes the location (z = 100 mm) where the space constant of the axon suddenly doubles and the upward arrow denotes the location (z = 25 mm) of the recording electrode. Note that for recording electrodes near the axon only the traveling wave is noted but when the electrodes are placed far from the axon, only potentials generated as the impulse reaches the boundary are evident.