  A gross estimate of the neutron skin [0.80(5)$(N-Z)/A$ fm] is extracted from
experimental proton radii, represented by a four parameter fit, and observed
mirror displacement energies (CDE). The calculation of the latter relies on an
accurately derived Coulomb energy and smooth averages of the charge symmetry
breaking potentials constrained to state of the art values. The only free
parameter is the neutron skin itself. The Nolen Schiffer anomaly is reduced to
small deviations (rms=127 keV) that exhibit a secular trend. It is argued that
with state of the art shell model calculations the anomaly should disappear.
Highly accurate fits to proton radii emerge as a fringe benefit.
