  Some mathematical aspects of using the translation group as an internal
symmetry group in a gauge field theory are presented and discussed. The
traditional manner in which gravitation can be accounted for by the
introduction of a global frame field on a parallelizable spacetime is reviewed.
It is then discussed in the more general context of a global frame field on the
bundle of linear frames. In the process, the elements of variational field
theory for physical fields defined on G-structures are set down. It is
suggested that it is probably more proper to attribute gravitation to a
reduction of the bundle of linear frames to {e} -- at least over a generic
submanifold of spacetime -- than to a reduction to the Lorentz group since the
Lorentz group is more intrinsic to electromagnetism and gravitation has the
character of a "residual" symmetry of spacetime at the astrophysical level.
