  We use Kaufman's spinor method to calculate the bulk, surface and corner free
energies $f_b, f_s, f_s', f_c$ of the anisotropic square lattice zero-field
Ising model for the ordered ferromagnetic case. For $f_b, f_s, f'_s$ our
results of course agree with the early work of Onsager, McCoy and Wu. We also
find agreement with the conjectures made by Vernier and Jacobsen (VJ) for the
isotropic case. We note that the corner free energy $f_c$ depends only on the
elliptic modulus $k$ that enters the working, and not on the argument $v$,
which means that VJ's conjecture applies for the full anisotropic model. The
only aspect of this paper that is new is the actual derivation of $f_c$, but by
reporting all four free energies together we can see interesting structures
linking them.
