  We collect three observations on the homology for Smale spaces defined by
Putnam. The definition of such homology groups involves four complexes. It is
shown here that a simple convergence theorem for spectral sequences can be used
to prove that all complexes yield the same homology. Furthermore, we introduce
a simplicial framework by which the various complexes can be understood as
suitable "symmetric" Moore complexes associated to the simplicial structure.
The last section discusses projective resolutions in the context of dynamical
systems. It is shown that the projective cover of a Smale space is realized by
the system of shift spaces and factor maps onto it.
