  Gaudin hamiltonians form families of r-dimensional abelian Lie subalgebras of
the holonomy Lie algebra of the arrangement of reflection hyperplanes of a
Coxeter group of rank r. We consider the set of principal Gaudin subalgebras,
which is the closure in the appropriate Grassmannian of the set of spans of
Gaudin hamiltonians. We show that principal Gaudin subalgebras form a smooth
projective variety isomorphic to the De Concini-Procesi compactification of the
projectivized complement of the arrangement of reflection hyperplanes.
