over sufficiently
conducting ground it may be a reasonable approximation to
neglect the propagation effects on the transients on the line.
The results show that for lines of several kilometers length
over moderately conducting ground the effects of propagation
on the transients as they propagate along the line may not
be neglected. In these cases the approximation 5) is only
valid if the impedance due to ground can be replaced by a
constant resistance. To test this possibility the quantity