2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/10323We investigate the influence that projection effects have on the completeness of the the Abell cluster catalogue in the context of an $Ω_0$=1 CDM Universe. We construct a galaxy catalogue and identify clusters using an algorithm that mimics Abell's method. Over 30% of Richness Class $\geq$1 clusters have been selected despite not meeting the required intrinsic (3D) richness criterion. Velocity dispersions are shown to have been systematically overestimated.6 pages, including 2 figures, to appear in proceedings ``Mapping, Measuring and Modelling the Universe'', Valencia 1995, eds. P. Coles & V. MartinezAstrophysicstext