A construction is given whereby
a Riemannian manifold induces a Riemannian metric on the total space of a large
class of fibre bundles over it. Using this metric on the appropriate bundles, necessary
and sufficient conditions are given for the Gauss map and the spherical Gauss map to
be harmonic. A weak maximum principle is applied to the Gauss map of an
isometric immersion into Euclidean space in order to prove a sufficient condition
for when such an immersion with parallel mean curvature vector must be
minimal.