  The simple leaky-box model of propagation of cosmic rays in the Galaxy is
quite suitable for handling data on cosmic ray nuclei energy spectra and
composition at E ? 1 GeV [1,2]. In the leakybox model a full information about
cosmic ray propagation in Galaxy is compressed to the single parameter - escape
length, Xe, characterizing mean grams of a matter passed by cosmic rays from
sources to the Earth. In this paper we analyze the world data on proton and
iron cosmic ray spectra collected in the past (HEAO, CRN et al.) and in series
of recent electronic experiments (ATIC, CREAM, MS, BESS, Tracer et al.) and
obtain the rigidity dependence of escape length, Xe(R) = R^(-0.47\pm-0.03),
from the measured rigidity dependence of the protons/iron ratio. It quite
agrees with the one stimated in standard manner from the secondary/primary
nuclei ratio. But at R > 300 GV the behavior of Xe(R)distinctly changes, that
can (variant of explanation)point out to the change of proton/iron ratio in
cosmic ray sources.
