  Pulse propagation in nonlinear arrays continues to be of interest because it
provides a possible mechanism for energy transfer with little dispersion. Here
we show that common measures of pulse dispersion might be misleading; in
strongly anharmonic systems they tend to reflect a succession of extremely
narrow pulses traveling at decreasing velocities rather than the actual width
of a single pulse. We present analytic estimates for the fraction of the
initial energy that travels in the leading pulses. We also provide analytic
predictions for the leading pulse velocity in a Fermi-Pasta-Ulam beta-chain.
