  By assuming the existence of a pseudopotential smooth enough to do
Hartree-Fock variations and good enough to describe nuclear structure, we
construct mass formulae that rely on general scaling arguments and on a
schematic reading of shell model calculations. Fits to 1751 known binding
energies for N,Z$\geq 8$ lead to RMS errors of 614 keV with 14 parameters and
388 keV with 28 parameters. The latter is easily reduced to a 20 parameter form
at 423 keV.
