1. We are considering the recovery time here merely as the time required for the potential of the wire to change from its maximum negative value to 1∕eth of that value.
2. In order to simplify the discussion of Fig. 1D, it was implied that Vʹ passes through the pointcat exactly the instant in which the counter wire assumes its maximum negative value. Actually, Vʹ lags behind a time whose order of magnitude is about 3×10−5 second. The error introduced by this lag may be neglected, however, since the timeT, indicated bybd, is quite long in comparison.