  A hard sphere fluid confined by hard, structureless, and parallel walls is
investigated using a certain version of weighted density functional theory. The
density profile, the excess coverage, the finite size contribution to the free
energy, the solvation force, and the total correlation function are determined
as function of the slit width $L$ for various bulk number densities $\rho_b$.
In quantitative agreement with rigorous results the present version of density
functional theory yields a constant and large but finite number density profile
for the limiting case that $L$ is reduced to the diameter of the hard spheres.
Within the Derjaguin approximation the results for the slit geometry allows us
to obtain the solvation force between two large hard spheres immersed into a
fluid of much smaller hard spheres.
