  The pion-nucleon bremsstrahlung $\pi+N\Longrightarrow\gamma'+\pi'+N'$ is
studied in a new form of current conservation. According to this condition, the
internal and external particle radiation parts of the $\pi N$ radiation
amplitude have opposite signs, i.e., they contain terms which must cancel each
other.
  Therefore, one has a screening of the internal and external particle
radiation in the $\pi N$ bremsstrahlung. In particular, it is shown that the
double $\Delta$ exchange diagram with the $\Delta-\gamma' \Delta'$ vertex
cancel against the appropriate longitudinal part of the external particle
radiation diagrams. Consequently, a model independent relation between the
magnetic dipole moments of the $\Delta^+$ and $\Delta^{++}$ resonances and the
anomalous magnetic moment of the proton $\mu_p$ is obtained, where
$\mu_{\Delta}$ is expressed by $\mu_p$ as $\mu_{\Delta^+}={{M_{\Delta}}\over
{m_p}} \mu_p$ and $\mu_{\Delta^{++}}={3\over 2}\mu_{\Delta^+}$ in agreement
with the values extracted from the fit for the experimental cross section of
the $\pi^+ p\to\gamma'\pi^+ p$ reaction.
