  The gravitational properties of a torus are investigated. It is shown that a
torus can be formed from test particles orbiting in the gravitational field of
a central mass. In this case, a toroidal distribution is achieved because of
the significant spread of inclinations and eccentricities of the orbits. To
investigate the self-gravity of the torus we consider the $N$-body problem for
a torus located in the gravitational field of a central mass. It is shown that
in the equilibrium state the cross-section of the torus is oval with a Gaussian
density distribution. The dependence of the obscuring efficiency on torus
inclination is found.
