  The finite size dependent enhancement of pairing in mesoscopic Fermi systems
is studied under the assumption that the BCS approach is valid and that the two
body force is size independent. Different systems are investigated such as
superconducting metallic grains and films as well atomic nuclei. It is shown
that the finite size enhancement of pairing in these systems is in part due to
the presence of a surface which accounts quite well for the data of nuclei and
explains a good fraction of the enhancement in Al grains.
