  We apply fractal analysis methods to investigate the scaling properties in
the Abell and ACO catalogs of rich galaxy clusters. We also discuss different
technical aspects of the method when applied to data sets with small number of
points as the cluster catalogs. Results are compared with simulations based on
the Zel'dovich approximation. We limit our analysis to scales less than 100
$\hm$. The cluster distribution show a scale invariant multifractal behavior in
a limited scale range. For the Abell catalog this range is 15--60$\hm$, while
for the ACO sample it extends to smaller scales. Despite this difference in the
extension of the scale--range where scale--invariant clustering takes place,
both samples are characterized by remarkably similar multifractal spectra in
the corresponding scaling regime. In particular, the correlation dimension
turns out to be $D_2\simeq 2.2$ for both Abell and ACO clusters. Although it is
difficult to point out the scale at which homogeneity is reached with the
present size of these redshift surveys, our results indicate that the cluster
distribution shows a tendency to homogeneity at large scales, disproving the
picture of a pure scale invariant fractal structure extending to arbitrarily
large distances.
