  We determine the mass profile of an ensemble cluster built from 3056 galaxies
in 59 nearby clusters observed in the ESO Nearby Abell Cluster Survey. The mass
profile is derived from the distribution and kinematics of the Early-type
(elliptical and S0) galaxies only, which are most likely to meet the conditions
for the application of the Jeans equation. We assume that the Early-type
galaxies have isotropic orbits, as supported by the shape of their velocity
distribution. The brightest ellipticals (with M_R < -22+5 log h), and the
Early-type galaxies in subclusters are excluded from the sample. Application of
the Jeans equation yields a non-parametric estimate of the cumulative mass
profile M(<r), which has a logarithmic slope of -2.4 +/- 0.4 in the density
profile at the virial radius. We compare our result with several analytical
models from the literature (NFW, Moore et al. 1999, softened isothermal sphere,
and Burkert 1995) and find that all are acceptable. However, our data do not
provide compelling evidence for the existence of a core; as a matter of fact,
the best-fitting core models have core-radii well below 100/h kpc. The upper
limit we put on the size of the core-radius provides a constraint for the
scattering cross-section of dark matter particles. The total-mass density
appears to be traced remarkably well by the luminosity density of the
Early-type galaxies. On the contrary, the luminosity density of the brightest
ellipticals increases faster towards the center than the mass density, while
the luminosity density profiles of the early and late spirals are somewhat
flatter than the mass density profile. (Abridged)
