  The flat Harris current sheet model has become a powerful initial equilibrium
in theory and simulation of magnetic reconnection in the magnetotail, at the
magnetopause and also in multiple current sheet models of the heliosheath and
astrophysics, where it is believed that such structures may become responsible
for generation of turbulence and also high energy particles. Here we
investigate the philosophy behind the Harris sheet in view of the physical
conditions. The kinematic treatment in this note takes care of the different
dynamics of ions and electrons.
