  With the establishment of vanishing net electrostatic fields in a toroidally
symmetric tokamak at equilibrium [R. W. Johnson, to appear in Phys. Rev. D],
one is left needing an explanation for the measurement of an apparent radial
electric field in experiments. Two scenarios are proposed, depending on the
type of measurement being considered. Indirect measurement via the radial
equation of motion for an impurity species possibly measures that species' net
radial viscous force, and direct measurement via the motional Stark effect
might reveal electric fields generated by the shifting of the toroidal magnetic
flux density.
